If you’re aiming to get into top science institutes like IISERs or NISER, cracking these exams is your ticket. But let’s be real—these aren’t just any tests. They’re highly competitive, and scoring well demands more than just hard work.

You need:

✔ A clear strategy – Knowing what to study and how to study

✔ Smart time management – Balancing speed and accuracy

✔ The right resources – Quality study material and guidance

Whether it’s IAT (for IISERs) or NEST (for NISER & CEBS), your preparation needs to be sharp, focused, and efficient. Because when thousands of bright students are competing for limited seats, every minute (and every mark) counts.

Stay Tuned!

Understanding IAT 2025 and NEST 2025 Exam Pattern

Before diving into preparation, let’s understand the exam structure and syllabus for both exams.

IAT 2025 Exam Pattern (IISER Aptitude Test)

• Mode: Computer-Based Test (CBT)
• Duration: 3 Hours
• Total Marks: 240
• Subjects & Marking:
  • Physics: 60 marks
  • Chemistry: 60 marks
  • Mathematics: 60 marks
  • Biology: 60 marks
• Marking Scheme: (+4) for each correct answer and (-1) for each wrong answer.

NEST 2025 Exam Pattern (National Entrance Screening Test)

• Mode: Computer-Based Test (CBT)
• Duration: 3.5 Hours
• Total Marks:  240
• Subjects & Marking:
  • Physics: 60 marks 
  • Chemistry:60 marks
  • Mathematics:60 marks
  • Biology: 60 marks

The merit list for both institutes will be prepared using the best three scores out of the four sections, and the section with the worst score will not be considered. That is, scores out of 180 will be considered for preparing the merit list. 

Preparation Strategy for IAT & NEST 2025

Step 1: Know the Syllabus & Exam Pattern

The first step to crack any exam is to have a clear and realistic study plan that suits your learning style and goals. Here are some steps to create a study plan for IAT.

• Know the syllabus and exam pattern: The syllabus for IAT covers the topics from Class 11 and 12 NCERT textbooks of Physics, Chemistry, Mathematics, and Biology. The exam pattern consists of multiple-choice questions (MCQs) with negative markings. The duration of the exam is 3 hours for IAT. You should familiarize yourself with the syllabus and exam pattern and identify your strengths and weaknesses.
• Divide your time wisely: You should allocate your time according to the weightage of each subject and topic in the exam. You should also consider your level of preparation and interest in each subject. 

Step 2: Build Strong Fundamentals

• NCERT (Class 11 & 12) is the foundation for both exams.
• Use reference books like:

Best Books for NEST and IAT 2025:

The right books can make a difference between an average attempt and a stellar performance. Physics

• Concepts of Physics (Vol 1 & 2) – H.C. Verma (For clarity and strong conceptual understanding)
• Fundamentals of Physics – Halliday, Resnick & Walker (For deeper insight and problem-solving)
• Problems in General Physics – I.E. Irodov (For advanced questions and conceptual clarity)

Chemistry

• Physical Chemistry – P. Bahadur (Best for numerical problems)
• Organic Chemistry – Morrison & Boyd / Solomon & Fryhle (For in-depth understanding)
• Inorganic Chemistry – J.D. Lee / NCERT (For building strong fundamentals)

Mathematics

• IIT Mathematics – M.L. Khanna (For extensive problem-solving)
• Cengage Series / Arihant Series (For topic-wise practice)
• NCERT Mathematics (Class 11 & 12) (For basics and direct questions)

Biology

• NCERT Biology (Class 11 & 12) (Absolutely essential!)
• Trueman’s Biology (For a little extra detail)
• Dinesh Objective Biology (For practice questions)

Step 3: Practice & Mock Tests

• • Platforms like SciAstra offer structured test series and doubt-solving sessions.

• The magic of Mock tests. They mimic the real exam environment, helping you get familiar with:

1. Question Distribution: You’ll know which topics get the most attention.
2. Time Management: No more running out of time—you’ll know exactly how to pace yourself.
3. Exam Strategy: You’ll discover your own flow—whether it’s answering easy questions first or tackling the tough ones head-on.
4. Boost Accuracy and Avoid Negative Marking.
5. For IAT: IISER Aptitude Test Mock Book 2025 
6. For NEST: NEST Mock Book 2025

SciAstra Online Course for IISC, IISER, NISER, ISI, CMI, CEBS,IACS • SciAstra

Step 4: Time Management & Revision

• Allocate time wisely between subjects.
• Revise formulas, diagrams, and key concepts regularly.

 How SciAstra Can Help You Crack IAT & NEST?

SciAstra is a leading mentoring platform for students preparing for competitive science exams like IAT, NEST etc. Here’s how they can help:

✅ Expert Guidance: Learn from mentors who’ve cracked IISER, NISER etc.

✅ Structured Study Material: Well-researched notes and practice questions.

✅ Mock Tests & Analysis: Simulate real exam conditions and track progress.

✅ Doubt Clearing Sessions: Personalized support for weak areas.

(SciAstra’s courses are designed to align with the latest IAT & NEST patterns, ensuring you’re always on the right track.)

Resourses:

To further enhance your IAT preparation, consider taking SciAstra’s courses, such as the Vikram 2.0 Batch (IAT & NEST 2025) with a Crash Course in Hinglish, the Kalam Batch (IAT & NEST 2025) with a Crash Course in English, or the Homi Batch 2026 for Class 11th (IAT & NEST 2026).

Enroll Now! Click here to learn more about these courses.

Check here for further guidance on the best books for IAT. 

 Last-Minute Tips for IAT & NEST 2025

• Stay Calm & Confident: Avoid last-minute cramming.
• Focus on Strengths: Prioritize high-weightage topics.
• Avoid Guesswork: Negative marking can hurt your score.
• Stay Updated: Check official websites for any changes.

About us: Sciastra

At SciAstra, we guide students who want to become scientists and pursue research by helping them secure admissions in the top colleges for the same like IISER, NISER, CEBS, ICAR, CMI, etc.

Our mentors are from the top research institutes like IISER, NISER, IACS, CMI, ISI, IISC Bangalore, and so on. If you are looking to prepare for IAT / NEST 2025, you can check out our courses and get access to live classes, recorded lectures, study material, mock tests, doubt-clearing classes, and much more!

To know more about us, click here OR download the SciAstra App from Play Store or App Store!