Hello Nidhi

You have to read Lucent for(G.K except economic portion), previous year question paper, Maths up to 10th standard (basic math)Hindi from aaditya publication.math is so important in 3 year llb entrance examination because since last 3 to 4 years 40 questions came in each year.as far as current affairs are concerned you can read pratiyogita darpan.Thats enough for securing admission in LL.b 3 year course.

Subhash kashyap for constitution

Elementary math at 10th level

General english

Hindi from lucent

Universal guide for clat.

You just have to follow the current affairs for last 6 months before the BHU LLB. You should read static Gk in English your main focus should be on vocabulary and Grammar portion ,in maths you need to prepare maths of up to 10th standard, in legal you have to be prepared for legal reasoning as well as legal knowledge.

Good Luck!