Assuming asking for IBPS PO. The key to good preparation for IBPS PO examination is to understand the exam pattern and study from the right resources.

Some of the books for individual sections that have standard questions to clear your basic can be as follows:

Quantitative aptitude

1. Quantitative Aptitude for competitive examinations by Dr. R.S Aggarwal
2. Quantitative Aptitude Test by N.K Singh
3. Books of Arihant Publications

Reasoning

1. A modern approach to verbal and non-verbal reasoning by Dr. R.S Aggarwal
2. A New Approach to Reasoning Verbal & Non-Verbal by B.S. Sijwali
3. Analytical Reasoning by M.K. Pandey

English

1. English (From Plinth to Paramount) by Neetu Singh
2. Objective General English by SP Bakshi
3. High School English Grammar By Wren and Martin

Banking Awareness

1. Banking Awareness by Arihant
2. Banking Awareness by Disha Publications

Here are some preparation tips you can follow

Know the Syllabus & Understand the exam pattern first.

Go through with previous year papers & do practise with that.

Make a proper timetable for your study Section & topic wise.

Make your own Notes as per your convenience.

 Know your weak areas & Do practise as much you can on that.

Stay Updated with Current Affairs. Read News paper, Magzines & General awareness books.

Join Mock Test to analyze your performance.

Good Luck!