See SL Loney is very standard book for Mathematics and if you are preparing for JEE-Advance then it is must have book according to my personal experience and if you consider it for Trigonometric and geometric part then it is the good thing but to only depend upon one book for for JEE-Main and JEE-Advance would not be the wise decision so for Mathematics as well as for other two subjects I am enlisting down some best books for preparation of JEE-Main and JEE-Advance 2021 :-

JEE-Main 2021

@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

JEE-Advance 2021

@Physics

Concepts of Physics by H C Verma (Vol-1 and Vol-2)

Fundamentals of Physics by David Halliday/Resnick/Walker

IIT JEE Physics by Arihant (35 years Chapterwise Solved Papers 2013-1979)

@Mathematics

SL Loney Mathematics

Objective Mathematics By R.D. Sharma

Plane Trigonometry and Coordinate Geometry (Two Books) by S.L Loney

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

Integral Calculus for IIT-JEE by Amit M Agarwal (Arihant Publications)

A Text Book of Algebra For JEE Main & Advanced by Dr. SK Goyal (Arihant Publications)

@Chemistry

Physical Chemistry by OP Tandon

Modern Approach to Chemical Calculations by R.C. Mukherjee

Organic Chemistry by O.P. Tandon

Organic Chemistry by Paula Bruice Yurkanis

Organic Chemistry by Morrison & Boyd

Inorganic Chemistry by J.D Lee

Inorganic Chemistry by O P Tandon

If you are preparing for JEE-Advance then you can check out the link given below for best preparation tips :-

https://engineering.careers360.com/articles/jee-advanced-preparation-tips-physics-chemistry-and-mathematics

You can also check out the complete JEE-Advance 2021 syllabus from the link given below :-

https://engineering.careers360.com/articles/jee-advanced-syllabus

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!!