Hi Biswabijoy,

The best books to refer to prepare for bank POs are:

Quants:

RS Agarwal,  Fast Track Objective Arithmetic by Rajesh Varma, Magical book on Quicker Maths by Tyra

English:

Objective General English by R. S. Agarwal and Vikas Agarwal, Past papers.

Reasoning:

A Modern approach Verbal and Non-Verbal Reasoning by Sijwali.

Please  solve mocks and past papers for best preparation.

All the best!