Hey Aamir.

Its great that you are opting law as a career. Coming to your question,  following points might help you with your preparation.

1.purchase the clat preparation book of arihant.this book is very efficient for amu and jmi ballb preparation also. Also if could get - CLAT Study Kit: Legal Reasoning, English, Logical Reasoning, Mathematics and Legal Awareness and General Knowledge by Deepu Krishna and Remya Krishna, it would be very helpful to you.

2.current affairs can be covered by reading newspaper. Also keep a track of the current affairs from May 2017.

3.look for sample papers and previous years question papera and solve them. This wull help yoh incredibly

4.reasoning and english can only be prepared by solving papera and practicing. Solve the previous years papers and sample papers.

5.legal reasoning and knowledge questions will also come with practice. 

6.constitution from 11th class ncert

Hope this serves your query. Please feel free to respond and ask further questions.

All the best.