I want to know about the most important chapters to qualify for JEE Mains in Physics.

Well, that's great, as you are preparing for JEE Advanced Physics. From my research, I would like to recommend some of the books and resources that will help you learn the basics and understand the concept:

1. Concept of Physics (Vol 1 and 2) by H.C. Verma

2. Understanding Physics Series by D.C. Pandey (Arihant)

3.  Fundamentals of Physics by Halliday, Resnick and Walker

4. Problem in General Physics by I.E Irodov 

5. Physics Galaxy by Ashish Arora.

6. Previous Year Question Book (likee PW 48 Years/Oswaal JEE Advanced Paper)

The first book to read would be 'Concepts of Physics (vol 1 and 2)' by H.C. Verma Why you should read this book first: because it will build strong basics, and you will understand the concept easily. This book explains each and every topic in simple language and helps you to learn problems step by step.

After that, you can read the 'Understanding Physics Series' by D.C. Pandey (Arihant). This book is divided into 5 parts (Mechanics 1, Mechanics 2, Waves and Thermodynamics, Electricity and Magnetism, and Optics and Modern Physics). This book has a lot of JEE Main and Advanced level questions that will help you to practice every type of problem.

The third book to read is 'Fundamentals of Physics' by Halliday, Resnick, and Walker. This book gives you a deep understanding of theory and helps you with the physics concept. This book will improve your theory and alternative methods.

The fourth book you can read is 'Problem in General Physics' by I.E. Irodov. This book has one of the toughest problems for JEE Advanced. This book helps you to develop speed and accuracy.

The fifth book you can read is 'Physics Galaxy' by Ashish Arora. This book covers all the conceptual gaps that you will not find in other books and contains advanced illustrations and tricky problems. 

The last book would be 'Previous Year Question Book (like PW 48 Years/Oswaal JEE Advanced Paper).' This book helps you to understand the real exam patterns. You will get to know how the questions are asked, and you will learn how to apply what you have learned. It will not only improve your timing but also build confidence in you.

I hope this will help.

Mamta Bankoti