Hello,

Well, prepare from the NCERT books first it helps you to understand the concept.

If you you to practice more than prefer these books;

For chemistry;

• Organic Chemistry by Morrison Boyd.
• Organic Chemistry by O.P. Tandon.
• Inorganic Chemistry by O.P. Tandon.
• Modern approach to chemical calculations by R.C. Mukherjee.
• Numerical Chemistry by P.Bahadur.
• Concise Inorganic Chemistry by J.D. Lee.

For Mathematics;

• IIT Mathematics by M.L. Khanna.
• Differential Calculus by A Das Gupta.
• Class XI and XII Mathematics by R.D. Sharma.
• Trigonometry, Geometry Books by S.L. Loney.
• Problems in Calculus of One Variable by I.A. Maron.
• Higher Algebra by Hall and Knight.

Hope this will help you. All the best.