IISER Aptitude Test (IAT)

The IISER Aptitude Test (IAT) is the primary national entrance examination for admission to the five-year BS–MS programmes offered by the Indian Institutes of Science Education and Research. The exam identifies students suited for research-focused science education by evaluating conceptual understanding across multiple scientific disciplines.

Selection Logic
Admission to IISER programmes is now primarily determined through the IAT score. With earlier admission routes such as KVPY discontinued, the IAT has become the dominant selection channel for these institutes, making performance in this exam the key factor for admission.

Exam Mechanics
The IISER Aptitude Test is conducted as a 3-hour computer-based examination containing 60 multiple-choice questions. The paper includes 15 questions each from Physics, Chemistry, Mathematics, and Biology, with +4 marks for correct answers and −1 mark for incorrect responses, making the maximum possible score 240 marks.

Strategic Insight
A unique feature of the exam is that all four science subjects appear in the paper even though candidates are typically required to study only three subjects in Class 12 for eligibility. Biology section in IAT often contains 5–7 “direct” questions based on NCERT definitions that can be solved in seconds. Securing these 20–28 marks without complex calculations is often the difference between getting IISER Pune/Kolkata versus a newer campus.

Admission Mechanics
After the exam, candidates participate in a centralised counselling process where seats are allocated across IISER campuses according to entrance rank and candidate preference. Several other research-focused programmes also accept IAT scores, expanding the number of institutions using the same merit list. If you are aiming for B.Tech (Bhopal) or BS-MS (Kolkata Data Science), you must have studied Mathematics in Class 12.

Competition Signal
The IISER system collectively admits roughly two thousand students each year across its campuses, making admission highly competitive for candidates interested in research-oriented science programmes.

Preparation Tip
A high-value preparation strategy is practising conceptual mixed-subject problems rather than solving chapters in isolation. IAT questions often require applying basic principles quickly across different topics, so students who train themselves to recognise conceptual links between physics, chemistry, mathematics, and biology typically perform better.