Nitish , 31 Jan 2018
Firstly, do not make the mistake of surronding yourself with too many books. Stick to a certain set and only buy more books when you are done with the ones you have. For Physics, HC Verma has been the standard book for many years and still remains the undisputed king. Go for the Arihant book series for mathematics, especially calculus. For Chemistry, refer to P Bahadur for physical chemistry, NCERT textbooks for inorganic and OP Tandon for Organic. If you don't have much time and haven't given much time to preparation, forget it. Focus on JEE Mains by consulting NCERT.
Nikitin Sharma 25 Jul 2019
You need not many reference books to begin. Instead start with thorough study of NCERT textbooks that clear your concepts. If you had a focused study for 12th board JEE Mains preparation is not going to be difficult. There are so many reference books available, but concentrate only one or two from each subject. I believe R.D. Sharma and RS Aggarwal are best for Mathematics; HC Verma for Physics, and OP Tandon for Chemistry. You can also check Morrison & Boyd for Organic Chemistry. For practice of Chemical Calculation I took help of R.C. Mukherjee.