DRDO vs ISRO Scientist: GATE, Written Test, Pay and Postings Compared

14 Nov 2026

Quick answer

DRDO's Scientist 'B' and ISRO's Scientist/Engineer 'SC' are both Level 10 posts for engineers, but they select differently. DRDO uses GATE and an interview, with GATE carrying 80% of the merit. ISRO uses GATE or its own written test, each weighted 50:50 with an interview. This comparison sets out who each takes, the age and marks limits, the pay and how to choose.

DRDO and ISRO are the two research organisations most engineering graduates think of first, and their entry posts look alike on paper: both are Group 'A' scientist posts at Pay Level 10. The routes in are different enough that a candidate can be well placed for one and shut out of the other. This guide compares them from their latest official advertisements: DRDO's Advertisement No. 156 and ISRO's two 2026 advertisements, ICRB:02 and ICRB:03.

For the current ISRO cycle, see the ISRO Scientist exam page. For every engineering post open now, browse engineering vacancies or jobs for engineering graduates.

The Two Posts at a Glance

	DRDO Scientist 'B'	ISRO Scientist/Engineer 'SC'
Recruited by	Recruitment and Assessment Centre (RAC), Delhi	ISRO Centralised Recruitment Board (ICRB)
Degree	First-class B.E./B.Tech, or a first-class M.Sc in some disciplines	B.E./B.Tech with 65% or a CGPA of 6.84
Route	GATE score, then interview	GATE score, then interview; or ISRO's own written test, then interview
Final merit	80% GATE, 20% interview	50% GATE or written test, 50% interview
Upper age (unreserved)	35	28
Pay	Level 10, basic pay ₹56,100	Level 10, basic pay ₹56,100
Latest intake	152 posts (Advt. 156, closed 4 July 2025)	92 posts by GATE and 175 by written test (2026)

How Each Selects

DRDO recruits Scientist 'B' only on GATE. Advertisement No. 156 states that "The recruitment in the disciplines will be based on valid GATE Score (2023/2024/2025) and Personal Interview." RAC shortlists candidates by GATE score "in the ratio of 1:10" for each discipline and category. The final list is "on the basis of discipline wise category wise merit of aggregate of 80% weightage of marks of GATE score and 20% weightage of marks in Personal Interview."

The interview is a hard gate, though: unreserved candidates need at least 70% in it, and EWS, OBC, SC, ST and Divyangjan candidates at least 60%. Those who fall short "will not be considered for final selection irrespective of their GATE score."

ISRO ran two routes in 2026, each with its own advertisement:

The GATE route, Advt. ICRB:02(EMC-CEPO):2026. Candidates were screened on a GATE 2025 or GATE 2026 score, in the ratio of 1:7. The final panel gives "50% weightage ... to GATE Scores and 50% weightage to Interview marks." It covered 92 posts in electronics, mechanical, computer science, civil, electrical, refrigeration and air-conditioning, and architecture. ISRO has already published the selection panel for the electronics posts.
The written-test route, Advt. ICRB:03(EMC):2026. No GATE score is needed. A computer-based test has two parts: 80 discipline questions in 90 minutes, with minus one-third for each wrong answer, and 20 aptitude questions in 30 minutes with no negative marking. Unreserved candidates must score 50% in each part. Those shortlisted, at 1:5 with a minimum of 10, face an interview, and the final panel is 50% test and 50% interview. It covered 175 posts in electronics, mechanical and computer science. The test was moved from 19 October to 29 October 2026, and ISRO has since opened objections on its answer keys.

ISRO's interview is marked out of 100, under the same heads in both 2026 advertisements: technical knowledge 40, general awareness in the specialisation 20, presentation and communication 20, comprehension 10, and academic achievements 10. Those last 10 marks reward the college and the degree record: 3 for an IIT, IISc, IIST, NIT or an institute in NIRF's top 20, up to 4 for the grades (a CGPA of 9 or 85%), and 3 for an institute rank. DRDO's advertisement sets no such scale.

Who Can Apply

	DRDO	ISRO
Marks in the degree	"At least First Class". Where an institute has no first-class rule, 60%, or a CGPA of 6.75	65% (average of all semesters) or a CGPA of 6.84 on 10. A degree graded only in CGPA must meet 6.84: ISRO does not convert it to a percentage
Degrees taken	B.E./B.Tech in nine engineering disciplines; M.Sc in physics, chemistry and mathematics; a few psychology, statistics and entomology posts	B.E./B.Tech in the advertised disciplines (B.Arch for architecture). The 2026 ICRB advertisements took no M.Sc
Upper age	35 (UR/EWS), 38 (OBC), 40 (SC/ST), on the closing date	28, on the closing date. OBC, SC and ST relaxation applies only "wherever posts are reserved"
GATE score accepted	Valid for three years: 2023, 2024 or 2025 for Advt. 156	GATE 2025 or 2026 for the GATE route; none for the written-test route

Two of these differences decide most cases. Age: ISRO's limit of 28 is seven years below DRDO's, so a 30-year-old unreserved engineer can still apply to DRDO but not to ISRO. Marks: a first-class degree at 62% is enough for DRDO but below ISRO's 65%. ISRO's GATE advertisement also says graduation "should have been completed within the stipulated duration of the course".

Fees are low for both. DRDO charges ₹100 to unreserved, EWS and OBC men, and nothing to SC, ST, Divyangjan and women candidates. ISRO's GATE route charged ₹250, with the same groups and ex-servicemen exempt. Its written-test route took ₹750 from everyone as a processing fee and refunds it to those who sit the test: in full to exempt candidates, and less the ₹250 fee to the rest.

Pay, Postings and Promotion

Pay is the same at entry. Both posts are in Level 10 of the pay matrix with a basic pay of ₹56,100, plus dearness allowance, house rent allowance and transport allowance. DRDO puts total emoluments at "approximately Rs. 1,00,000/- p.m. at the present metro city rate" on joining. ISRO lists medical facilities for the family, "limited quarters facility (in lieu of HRA)", leave travel concession and group insurance, and says new appointees are under the National Pension System or the Unified Pension Scheme. For how Level 10 compares with other engineering posts, see the engineering salary comparison.

Postings follow the work. DRDO is "a network of around 41 laboratories and 05 DRDO Young Scientist Laboratories" developing defence technologies. Its advertisement says selected candidates can be asked "to serve anywhere in India including remote/ field area locations", and appointment depends on a medical examination for Group 'A' technical posts "with Field Service liability." Not every Advt. 156 post is in DRDO itself: 9 were for the Aeronautical Development Agency, whose engineers "will not be part of DRDO", and 16 were posts in other Ministry of Defence establishments that "are not transferable to DRDO Establishments."

ISRO appointees "are liable to be posted in any of the Centres/Units" of ISRO and the Department of Space, and can be transferred among them. The 2026 GATE advertisement named likely postings for each discipline, including VSSC Thiruvananthapuram, URSC Bengaluru, SDSC SHAR Sriharikota, SAC Ahmedabad, NRSC Hyderabad and IPRC Mahendragiri.

Promotion is merit-based in both, and outside the common scheme. DoPT's 2024 order on promoting scientists notes that DRDO and the Department of Space follow "another scheme called Merit Based Promotion Scheme" rather than DoPT's own. ISRO's advertisement describes its scheme as one in which "Promotion to higher levels is delinked from availability of vacancy." How the grades and pay levels above the entry grade work across government is explained in scientist jobs in government.

Which to Target

You have a strong GATE score and are under 28 with 65%. Apply to both. GATE carries 80% of DRDO's merit and half of ISRO's on its GATE route.
Your GATE score is modest, or you have not taken GATE. ISRO's written-test route is the only one of the three that does not need it. DRDO will not consider you without a valid score. The guide to engineering jobs without GATE lists other routes.
You are over 28, or your degree is between 60% and 65%. DRDO is open to you. ISRO is not, unless an age relaxation covers you; there is none on marks.
You hold an M.Sc in physics, chemistry or mathematics. DRDO's Scientist 'B' takes a first-class M.Sc with a GATE score in the subject. ISRO's 2026 central advertisements did not. See jobs for M.Sc holders.
You studied civil engineering or architecture. ISRO's GATE route had civil and architecture posts for its construction wing, CEPO. DRDO's Advt. 156 had one civil post.

DRDO's next intake is coming. On 31 August 2026, RAC said it "would be notifying vacancies of Scientist 'B' for the year 2027 in the next few months" and encouraged aspirants "to appear for GATE 2027." For how PSUs use the same score, see GATE for PSU recruitment.

Frequently Asked Questions

Is GATE compulsory for DRDO and ISRO?

For DRDO's Scientist 'B', yes: shortlisting and 80% of the final merit are on GATE score. For ISRO, no: it ran a GATE route and a separate written-test route in 2026.

Which pays more, DRDO or ISRO?

Neither, at entry. Both posts are at Pay Level 10 with a basic pay of ₹56,100. DRDO estimates about ₹1,00,000 a month in total at the metro rate.

What is the age limit for ISRO and DRDO scientist posts?

ISRO's limit is 28, with OBC, SC and ST relaxation only where posts are reserved. DRDO's is 35 for unreserved and EWS candidates, 38 for OBC and 40 for SC and ST.

Can an M.Sc graduate become a DRDO or ISRO scientist?

At DRDO, yes, in disciplines such as physics, chemistry and mathematics, with a first-class M.Sc and a valid GATE score. ISRO's 2026 ICRB advertisements were for engineering and architecture graduates only.

How long is a GATE score valid for DRDO?

Three years, according to RAC's public notice of 31 August 2026. Advertisement No. 156 accepted GATE 2023, 2024 and 2025 scores.

In Summary

DRDO's Scientist 'B' and ISRO's Scientist/Engineer 'SC' pay the same, at Level 10 with ₹56,100 basic, and both promote under a merit-based scheme of their own. They differ at the door. DRDO selects only on GATE, weighted 80%, and takes candidates up to 35 with a first-class degree, including some M.Sc holders. ISRO takes engineers up to 28 with 65%, through GATE or its own written test, each weighted 50:50 with an interview that also scores the candidate's college and grades. DRDO's 2027 intake is due in the coming months.

Sources

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