Hi Akansha, 

You can refer these books for isi Kolkata:

TEST OF MATHEMATICS AT THE 10+2 LEVEL by the INDIAN STATISTICAL INSTITUTE.

Mathematical Problems With Elementary Solutions by A. M. Yaglon.

Introduction to the Theory of Numbers by I. Niven and H. S. Zuckerman.

Also if you know exact syllabus you can use jee books too!!

Concepts of topics would be always same. 

Thanks for being here at careers360.

All the best!

• Follow the right(not many) books. Keep the sources minimal but be thorough with whatever you have chosen. Books like SL Loney, Cengage, I.A Maronfor maths, HC Verma for physics, NCERT, JD Lee, Morrison boyd for chemistry.

All the very best and good luck.