You should weekly devote 4hours on weekdays out of which 2hours each for Jeemain and Board studies be given. 

On weekends you shall need to stretch to 8hours where 4hours each for both are required. 

In last 3montgs before Jeemain you must onky focus on appearjng mock exams daily and revision and analysis of mock exams. 

Make sure you start studying after 10th board exams so you have good basics and can understand fundamental better.