Hello Ashutosh,

The best book for IIT JEE Mains is NCERT.

Apart from NCERT books some other books are also available these are:

1. For Physics

Concepts of Physics (Part I) by  HC Verma

Concepts of Physics (Part II) by HC Verma

IIT JEE Physics by DC Pandey

Problems in General Physics by  I.E. Irodov

Physics for IIT-JEE by  Resnick, Halliday, Walker

Problems in Physics by S.S. Krotov

2. For chemistry

Organic Chemistry by Morrison Boyd

Organic Chemistry by O.P Tandon

Modern Approach to Chemical Calculations by R.C. Mukherjee

Numerical Chemistry by P. Bahadur

Concise Inorganic Chemistry by J.D. Lee

3. For Mathematics

IIT Mathematics by M.L. Khanna

Differential Calculus by A Das Gupta

Class XI & XII Mathematics by R.D. Sharma

Objective Mathematics for JEE by R.D. Sharma

Trigonometry, Geometry Books  by S.L. Loney

Problems in Calculus of One Variable by I.A. Maron

Higher Algebra by Hall and Knight

Hope this will help you. All the best.