IISER / IAT Exam Pattern

IISER Aptitude Test (IAT) is the entrance exam for admission to IISER undergraduate science programs.
Current pattern is broadly:

  • Mode: Computer Based Test (CBT)

  • Duration: 3 hours

  • Questions: 60 MCQs

  • Subjects: Physics, Chemistry, Mathematics, Biology

  • Distribution: 15 questions from each subject

  • Marks: +4 for correct, -1 for wrong

  • Maximum Marks: 240

Difficulty Level vs JEE Main

Short answer: IAT is usually more conceptual and less “speed-calculation heavy” than JEE Main, but it is not easy.

How it differs from JEE Main

  • JEE Main → mainly engineering-focused PCM

  • IAT → research/science-oriented and includes Biology too

  • IAT questions often feel:

    • more conceptual

    • more mixed across science thinking

    • sometimes less predictable

    • but still competitive because the seats are limited

Practical comparison

  • If a student is already good in JEE Main PCM, that helps a lot in IAT.

  • But IAT is not just “JEE Main lite” because:

    • Biology matters

    • question style can feel different

    • the exam is built for science/research admissions, not engineering only

So a fair line for students is:

JEE Main usually feels more speed- and calculation-driven, while IAT feels more concept-driven and research-oriented.
For PCM students, Biology becomes the biggest extra challenge in IAT.

person holding black academic hat
person holding black academic hat

IISER Colleges / Participating Institutes

The IISER admission system currently includes the main IISER campuses such as:

  • IISER Pune

  • IISER Kolkata

  • IISER Mohali

  • IISER Bhopal

  • IISER Thiruvananthapuram

  • IISER Tirupati

  • IISER Berhampur

Depending on the year and admission cycle, some other participating institutes / specific programs may also appear in the counselling/admission process, so for final website wording I’d keep this slightly flexible unless you want a fully year-specific table. Recent admission resources and student discussions also reference offerings such as special programs at IISER Bhopal and related participating institutes in some cycles.