Hi Nallamati,

If maths is your weak section start with the basics. As maths asked in the CAT exam is from the basic till 10th Standard. Practice daily at least 1 topic for 2-3 hours to get into the routine of solving questions. Once you'll be prepared with it, then start praticing questions from the previous years paper.

Arihant books are the best for prepartion. 

I hope I have cleared your doubt. Wish you all the best