These are some good books for JEE Mains. You will get great help from these.
1. Concepts of Physics (H.C.Verma)
2. Practice book physics for JEE mains and advanced (D.C. Pandey)
1. Organic Chemistry (Robert T. Morrison and Robert N. Boyd)
2. Concept of Organic Chemistry (O.P. Tandon)
1. IIT Mathematics (M.L.Khanna)
2. Objective Mathematics for JEE (R.D.Sharma)
Apart from these, you should solve the previous year question papers as well.
Hope this answer helps you.