Hello Asmit,

On the basis of the prescribed syllabus for the entrance exam it is advisable to keep in touch with following books:

• Objective General English by R.S. Agarwal.
• General Knowledge by Arihant Publications.
• Quantitative Aptitude for Competitive exams by R.S. Agarwal.
• Analytical Reasoning by M.K. Pandey.

Opinions may vary and people may suggest you other books and you are free to follow them, most of the books are not bad. You are not bound to follow the books stated above, they are just some examples, just keep in mind to go through one book completly, switching books always creates a hindrance. Pick one and stick to it. 

All the best.