IAT (IISER Aptitude Test) – 100 Days Preparation Strategy

The best 100-day strategy for IAT 2026 is a structured 3-phase plan: 35 days of foundation, 40 days of PYQs, and 25 days of mock tests. This approach helps you maximise marks even if you are starting late. You don’t need perfect preparation – you need exam-ready preparation. If you prepare smartly, 100 focused days are enough to transform your IAT performance. What matters most is not how late you start, but how effectively you use each phase.

100-Day Plan Overview

The most effective way to prepare for IAT is to break your journey into three focused phases. Each phase has a different purpose — first to build concepts, then to apply them, and finally to train under real exam conditions.

PhaseDaysFocusGoal
Foundation1–35NCERT + core conceptsBuild clarity and smart coverage
PYQs36–75Application + mistakesUnderstand pattern and improve accuracy
Mocks76–100Exam simulationTrain speed, stamina, and confidence

Phase 1: Foundation Building (Day 1–35)

The first 35 days are about building your base the right way. Don’t make the mistake of trying to finish every chapter quickly. Instead, focus on smart coverage — the chapters and concepts that give you the highest return in IAT.

  • Chemistry is the most scoring subject in IAT — read NCERT line-by-line and treat it as non-negotiable.
  • Build strong conceptual clarity instead of rushing through too many chapters.
  • Prioritise high-weightage chapters and modules first.
  • Use this phase to bridge your weak area if you come from a PCB or PCM background.
For PCB Students: You do not need to master all of Mathematics. Focus on high-yield chapters such as Conic Sections, Application of Derivatives, and Complex Numbers.
For PCM Students: Do not ignore Biology. Chapters like Genetics and Ecology are highly scoring and much more accessible than many students assume.

Phase 2: PYQs & Application (Day 36–75)

Once your foundation is ready, the next 40 days should be dedicated to converting theory into performance. This is where most students either level up or waste time. The key is to practise with intention.

  • Solve all PYQs from 2017 onwards to understand the actual IAT pattern.
  • Observe how questions test conceptual understanding rather than simple formula recall.
  • Identify repeated patterns, favourite chapter combinations, and common traps.
  • Use PYQ performance to guide your revision rather than revising everything equally.
Mistake Diary Method: Maintain a proper record of every error. Track whether a mistake happened due to concept gap, misreading, calculation, or panic.
Selective Revision: Instead of re-reading entire chapters, revise only the concepts where you consistently lose marks.

Practice PYQs – Tip

Many IAT questions are built around repeated concept patterns. Practising PYQs in an exam-like environment improves your speed, sharpens your thinking, and helps you control negative marking.

❯ Practice IAT PYQs

Phase 3: War Mode & Mock Tests (Day 76–100)

The final 25 days are all about becoming exam-ready. At this stage, your job is not to learn everything new — it is to train your mind and body to perform at peak level during the real exam.

  • Attempt full-length mock tests regularly in actual exam conditions.
  • Focus on improving speed, accuracy, stamina, and decision-making.
  • Use each mock to identify question selection mistakes and weak sections.
  • Keep your revision short, sharp, and based on test analysis.
Body Clock Training: Solve mocks from 9 AM – 12 PM so that your brain gets trained for the actual IAT exam timing.
Negative Marking Control: The best way to reduce silly mistakes is to practise under pressure and learn when not to attempt.

Final Strategy Summary

If you stay disciplined and follow the right process, 100 days are enough to create a huge improvement in your score. The goal is not random hard work — it is structured preparation.

PhaseAction
Phase 1NCERT + concept building + selective chapter focus
Phase 2PYQs + mistake diary + targeted revision
Phase 3Mocks + exam simulation + final polishing
Consistency beats perfection. If you stay disciplined for 100 days, you can absolutely put yourself in a strong position for IISER admission.
IAT Biology Trend Analysis IAT Chemistry Trend Analysis IAT Mathematics Trend Analysis IAT Physics Trend Analysis

FAQs on 100 Days IAT Preparation Strategy

Can I crack IAT 2026 in 100 days?

Yes. With a structured 3-phase strategy and consistent effort, it is absolutely possible to score well in IAT within 100 days.

What is the best 100-day strategy for IAT?

The most effective approach is: 35 days of foundation, 40 days of PYQs, and 25 days of mock tests and revision.

Is NCERT enough for IAT preparation?

NCERT is the most important resource, especially for Chemistry and Biology, but should always be combined with PYQs and mock tests.

Should PCB students study Mathematics for IAT?

Yes. Focusing on high-weightage chapters like Conic Sections, Application of Derivatives, and Complex Numbers can significantly improve your score.

How important are mock tests in IAT preparation?

Mock tests are critical for improving speed, accuracy, time management, and reducing negative marking.

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