What is the IISER Aptitude Test (IAAT) exam pattern?

IAAT is a 3-hour CBT with 60 questions (15 per subject: Physics, Chemistry, Mathematics, Biology) worth 3 marks each, totalling 180 marks with a −1 penalty for wrong answers. The exam tests aptitude for scientific research rather than rote knowledge, often presenting unfamiliar scenarios that require reasoning from first principles. The questions are typically harder than standard JEE Mains but test different skills — scientific reasoning and curiosity rather than speed in known problem types.

What is the IISER BS-MS dual degree program?

IISER offers a 5-year BS-MS dual degree in basic sciences across seven campuses: Pune, Kolkata, Mohali, Bhopal, Thiruvananthapuram, Tirupati, and Berhampur. Students choose their major in the third year from Physics, Chemistry, Mathematics, Biology, Earth Sciences, or Economics. The final 1.5 years involve intensive research thesis work. IISER graduates receive a research fellowship during their final-year thesis and are highly competitive for PhD admissions at IITs, TIFR, IISc, and top international universities.

How can I apply for IISER through IAAT?

Students can gain IISER admission through three channels: KVPY (SX stream) fellowship holders are directly eligible, JEE Advanced rank holders above a cutoff can apply without IAAT, and students can appear for IAAT specifically. For IAAT, students register on the IISER admissions portal, pay the application fee, and appear at designated exam centres. Admission through all three channels is merit-based, and seats are allocated through a centralized counselling process across all seven IISERs.

How competitive is admission to top IISERs through IAAT?

IISER Pune and IISER Kolkata are the most sought-after, and top ranks in IAAT or KVPY are required for admission there. IISER Mohali, Bhopal, and Thiruvananthapuram are also excellent choices with strong research infrastructure. The total intake across all 7 IISERs is approximately 1,500 students per year. Students admitted through IAAT must have scored in approximately the top 10–15% in that channel. JEE Advanced qualifiers with good ranks have a smoother admission path.

What is the career trajectory of IISER BS-MS graduates?

IISER BS-MS graduates are among the strongest candidates for research PhD programs globally. The five-year program with mandatory research training produces graduates with both strong theoretical foundations and hands-on research experience. A significant fraction of IISER graduates pursue PhD programs at MIT, Caltech, Harvard, Cambridge, ETH Zurich, and other top universities with full fellowships. Those who stay in India join top PhD programs at TIFR, IISc, IITs, and NCBs with a clear advantage over graduates from conventional BSc programs.

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IISER Aptitude Test IAAT Preparation Guide

IISERs (Pune, Kolkata, Mohali, Bhopal, Thiruvananthapuram, Tirupati, Berhampur)

Your Complete Preparation Guide for IISER Aptitude Test IAAT 2027 — strategy, study plan, tips & more.

DifficultyVery Hard

Total Marks60

Duration180 min

Start Practising Now →Free Mock Tests

Exam Overview

Mode

Computer Based Test (CBT)

Frequency

Annual

Next Exam Date

June 2027

EEligibility Criteria

Class 12 pass with PCB or PCM with minimum 60% marks; must not have attempted BS-MS earlier

ANumber of Attempts

Only fresh Class 12 or appearing students eligible

Study Plan by Subject

Biology

Week 1-4: Foundation

Core concepts & basics

Week 5-8: Deep Practice

Advanced problems & revision

Week 9-12: Mock Tests + Revision

Full-length tests & weak-area focus

Refer to official syllabus for complete topic list

Chemistry

Week 1-4: Foundation

Core concepts & basics

Week 5-8: Deep Practice

Advanced problems & revision

Week 9-12: Mock Tests + Revision

Full-length tests & weak-area focus

Refer to official syllabus for complete topic list

Mathematics

Week 1-4: Foundation

Core concepts & basics

Week 5-8: Deep Practice

Advanced problems & revision

Week 9-12: Mock Tests + Revision

Full-length tests & weak-area focus

Refer to official syllabus for complete topic list

Physics

Week 1-4: Foundation

Core concepts & basics

Week 5-8: Deep Practice

Advanced problems & revision

Week 9-12: Mock Tests + Revision

Full-length tests & weak-area focus

Refer to official syllabus for complete topic list

Expert Preparation Tips

IAAT rewards reasoning ability over formula memorization — practice reading scientific passages and inferring conclusions, not just solving standard problems from your Class 11–12 textbooks.

All four subjects carry equal marks, so balanced preparation is non-negotiable; identify your weakest subject early and dedicate extra practice sessions to bring it to par.

NCERT Physics, Chemistry, and Biology are the foundation; once those are strong, supplement with HC Verma for Physics and NCERT Exemplar problems for application-level practice.

Take full-length 3-hour mock tests under exam conditions at least 6 times before the exam to build stamina and learn to manage time across all four subject sections.

Exam Pattern at a Glance

Section	Questions	Marks	Duration (est.)
Biology	15	15	45 min
Chemistry	15	15	45 min
Mathematics	15	15	45 min
Physics	15	15	45 min
Total	60	60	180 min

Important Dates

Registration Opens

March–April 2027

Next Exam Date

June 2027

Conducted By

IISERs (Pune, Kolkata, Mohali, Bhopal, Thiruvananthapuram, Tirupati, Berhampur)

Frequently Asked Questions

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