Physics:

• Concepts of Physics, part 1 and 2 – H.C Verma

• NCERT Textbooks – Class 11th and 12th

• Understanding Physics series – D.C Pandey

Chemistry:

• NCERT Textbooks – Class 11th and 12th

• O.P Tandon books – Organic, Inorganic and Physical Chemistry

Mathematics:

• NCERT Textbooks – Class 11th and 12th

• R.D Sharma Mathematics

English:

• BITSAT English Proficiency and Logical Reasoning – Disha Publications

• The Pearson Complete Guide to BITSAT – One Learn Education

All round textbooks for BITSAT:

• A Complete Success Package for BITSAT – Arihant

• A Complete Guide to BITSAT – Disha Publications

All the very best and good luck.

Hii..

You should cover the basics of class 11th & 12th .You should prefer OP Tandon(for inorganic & general chemistry),Arihant Publications(for Organic Chemistry),HC Verma for Physics and RD Sharma for Maths.

Thanks..!!