Which books have you used for the JEE Main and the BITSAT?

There are several books you can refer to for the preparation of JEE Main and BITSAT exams. But the most important thing to do is to focus on NCERTs and practice online mock tests, previous year question papers, and question banks for every subject. It is equally important to study the exam pattern, type of questions, and syllabus of JEE Main and BITSAT before purchasing any reference book. 

Subjectwise Books for JEE Main and BITSAT-

Physics:

• Concepts of Physics by H.C. Verma: The best book for Physics. The book contains several practice questions for you to solve.
• Fundamental Physics by Halliday, Resnick, and Walker: It contains all the relevant topics.
• Understanding Physics by DC Pandey: This is the ideal book for JEE entrances; it covers all the relevant questions and topics. 
• Prep Guide to BITSAT by Arihant publications is a good book for BITSAT.

Chemistry:

• Physical Chemistry: Modern Approach to Chemical Calculations by RC Mukherjee. It contains several practice questions for your reference.
• Organic Chemistry: A book by Paula Y. Bruice: It is the best for clearing doubts and building a strong foundation in Organic Chemistry.
• Inorganic Chemistry: Concise Inorganic Chemistry by J.D.Lee: The book covers all the relevant topics and contains several questions
• The Cengage set of 6 books by KS Verma.

Mathematics:

• New Pattern JEE Mathematics Arihant Publications by SK Goyal.
• Algebra, Different Calculus, Integral Calculus, Vector, and 3D Geometry by Arihant Publication.
• A problem book in mathematical Analysis by G.N. Berman
• Mathematics for JEE Advanced by G.Tewani
• IIT Mathematics for JEE by M.L. Khanna.
• Play with graphs by Amit Agrawal.
• Algebra by G Tewani

All these books are great reference books for BITSAT and JEE Main but you must try to focus on NCERTs and practicing questions.