IISER IAT 2027 Eligibility: Subjects, Attempt Limit, Age Limit

To be eligible for IISER IAT 2027, you must have passed Class 12 with Physics, Chemistry, and Mathematics or Biology, securing at least 60% aggregate marks (55% for SC/ST/PwD), and must have passed Class 12 in 2026 or be appearing in 2027.

IISER IAT (Indian Institutes of Science Education and Research Aptitude Test) is the entrance exam for BS-MS dual degree programs at seven IISERs across India. The exam is held once a year, typically in June. Eligibility is strictly defined by your Class 12 subjects, passing year, and minimum percentage — verifying these before applying prevents a rejected form.

• Class 12 must include Physics, Chemistry, and Mathematics (PCM) or Physics, Chemistry, and Biology (PCB) as core subjects.
• Minimum aggregate of 60% in qualifying subjects is required; SC/ST/PwD students need 55%.
• Only students who passed Class 12 in 2026 or are appearing or passing in 2027 can apply — effectively capping IAT at a maximum of 2 attempts per student.
• There is no upper age limit for IISER IAT 2027; the Class 12 year restriction is the binding constraint.
• Both Indian nationals and OCI (Overseas Citizen of India) card holders are eligible.

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IISER IAT 2027 Eligibility Overview

IISER IAT 2027 eligibility rests on three main pillars: the subjects you studied in Class 12, the year you passed, and your aggregate percentage. The table below summarises all criteria at a glance.

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Class 12 Subjects Required for IISER IAT 2027

Your Class 12 subject combination is the first eligibility check for IISER IAT 2027. You must have studied one of the two approved combinations:

• PCM — Physics, Chemistry, Mathematics: Needed for BS-MS programs in Physical Sciences, Chemical Sciences, Mathematics and Statistics, Earth and Climate Science, and Data Science.
• PCB — Physics, Chemistry, Biology: Needed for BS-MS programs in Biological Sciences and Biotechnology.

Students who studied all four subjects (PCMB) are eligible for programs under both streams and have the widest choice of IISERs and departments. Physics and Chemistry are mandatory for every applicant; the third subject — Mathematics or Biology — determines which program streams are open to you.

If you studied Commerce or Humanities in Class 12, you are not eligible for IISER IAT 2027, regardless of your percentage or board.

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Minimum Marks Required in Class 12 for IISER IAT 2027

You need a minimum aggregate of 60% in your qualifying subjects — Physics, Chemistry, and your relevant third subject (Mathematics or Biology). The category-wise percentage requirement is as follows:

The aggregate is calculated only on the qualifying subject combination — Physics, Chemistry, and Mathematics or Biology. Your overall Class 12 percentage including languages and electives is not used for this check. Students who are appearing in Class 12 in 2027 can apply provisionally; final admission is confirmed only after their marksheet shows the required aggregate.

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IISER IAT 2027 Attempt Limit Explained

IISER IAT does not state a fixed number of permitted attempts. Instead, the attempt limit is an indirect result of the Class 12 passing year restriction. Because only students from the 2026 and 2027 batches are eligible for IAT 2027, each student can attempt IAT at most twice across their eligible window.

• A student who passed Class 12 in 2026 could attempt IAT in 2026 and again in 2027 — giving them exactly 2 attempts.
• A student appearing in Class 12 in 2027 can attempt IAT 2027 as their first attempt, and IAT 2028 as their second.
• Students who passed Class 12 in 2025 or before are not eligible for IAT 2027 under any circumstance.

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Age Limit for IISER IAT 2027

There is no upper age limit prescribed for IISER IAT 2027. You are not disqualified based on your date of birth. Because eligibility is restricted to students who passed Class 12 in 2026 or 2027, eligible students will generally be in the 17–21 year age range — this is an indirect outcome of the Class 12 year rule, not a formal age cap set by the conducting authority.

There is also no minimum age requirement beyond the implied minimum of having completed Class 12. Students who completed Class 12 earlier than usual are not penalised by any lower age threshold.

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Nationality and Other Eligibility Conditions

IISER IAT 2027 is open to the following applicants on the basis of nationality:

• Indian nationals — citizens of India holding a valid Indian passport or identity document.
• OCI (Overseas Citizen of India) card holders — subject to the same academic eligibility criteria (Class 12 subjects, percentage, and passing year) as Indian nationals.

Beyond nationality and academics, keep the following conditions in mind:

• You must not have already enrolled in a BS-MS or equivalent undergraduate science program at any IISER or equivalent institution, unless you have formally withdrawn before the IAT application deadline.
• Your Class 12 board must be recognised by the IISER admissions authority. All central boards (CBSE, CISCE) and state boards are accepted. International boards such as IB and Cambridge IGCSE are accepted for OCI applicants with appropriate equivalence documentation.
• Students admitted through alternative channels — JEE Advanced rank list or CUET — have separate eligibility rules specific to those channels and do not need to take IAT.

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