Hello Aspirant,

See NCERT Books are pre-requisite for JEE-Mains or any other competitive exam based on the syllabus of class 12th which means that if you are going to appear for JEE-Main then you must read the NCERT Books but only NCERT would not be enough for your preparation of JEE-Main because NCERT does not let you practice more and for that you need some side books so I am enlisting down some best books for preparation of JEE-Main :-

@Physics

Concepts of Physics-H. C. Verma

Fundamentals of Physics-Halliday, Resnick and Walker

Problems in General Physics-I. E. Irodov

University Physics-Freedman and Young

Understanding JEE physics series-DC Pandey

Problem In Physics-SS Krotov

@Mathematics

Higher Algebra-Hall and Knight

Coordinate Geometry-S.L. Loney

Differential and Integral Calculus-N. Piskunov

Calculus and Analytic Geometry-Thomas and Finney

IIT Mathematics for JEE Main & Advanced-M.L. Khanna

Course in Mathematics for IIT-JEE-Tata McGraw Hill publication

Problems Plus in IIT Mathematics-A Das Gupta

Trigonometry-S L Loney

@Chemistry

Modern Approach to Chemical Calculations-RC Mukherjee

Organic Chemistry-Solomons and Fryhle

Concise Inorganic-J. D. Lee

Organic Chemistry-Morrison and Boyd

University Chemistry-Freedman and Young

Physical Chemistry-N Awasthi

Arihant's Practice Book Chemistry for JEE Main And Advanced-R.K Gupta

For complete details kindly check out the link given below :-

https://engineering.careers360.com/articles/jee-main-preparation-tips-for-january-exam

You can also check out the JEE-Main knockout package for preparation of JEE-Main 2021 from the link given below :-

https://learn.careers360.com/knockout-jee-main-april/?product=27&icn=knockout-jee-main-2021-january&ici=

I hope this information helps you.

Good Luck!!