Hello Jayesh Shaw

Books recommended for WBJEE Maths preparations are-

1. NCERT Mathematics
2. Mathematics by R.S.Agrawal
3. Objective Mathematics by R.D. Sharma (Recommended)

One should have the basic idea of how to approach a question. These books will help you deal the same.

Also for more details about WBJEE and how to prepare and clear it, kindly visit the mentioned below pages.

https://engineering.careers360.com/articles/how-should-i-prepare-crack-wbjee-in-2019

https://engineering.careers360.com/articles/wbjee-2019

Hope it helps you.