You can refer past year problems to know about the level of questions asked in the exam.
You can also go through complete mock test series to analyze your preparation level.

You can solve NCERT books first for your preparation.

You can also follow below recommended books for your preparation

PHYSICS

1-Concepts of Physics Vol I and II by H.C. Verma
2-Fundamentals of Physics by Halliday, Resnick & Walker
3- Problems in General Physics by I.E. Irodov

MATHEMATICS

1- Maths XI & XII by R.D. Sharma
2- Plane Trigonometry Part 1 by S.L. Loney
3- Plane Co-ordinate Geometry by S.L. Loney
4- Higher Algebra by Hall and Knight
5- Problems in Calculus of One Variable by I.A. Maron

CHEMISTRY

1- Physical Chemistry by O.P. Tandon
2- Organic Chemistry by Paula Bruice Yurkanis
3- Organic Chemistry by O.P. Tandon
4- Inorganic Chemistry- Chemistry XI & XII by NCERT