Dear Swati, 

You can follow BHU cetacean test preparation books of Arihants and lucent's book of general knowledge. Apart from these you can focus on last 5-10 years previous question pairs which would give you a knowledge of which topics are mostly covered and asked according to weightage.

Both Arihants and lucent's gk books are good but if you have buyed any of them then read it thoroughly.

http://bhuonline.in/old-qus-paper-entr.html

It contains various questions. 

All the best.