Dear Vikrant,

It doesn't matter how much number of hours you are giving to your preparation try to give quality of time.

In order to do your revision if you want you can make your time table according to your comfort. So, that you can easily complete your revision on time. Set your daily and weekly targets. 

Focus on the chapters which holds more weightage in the exam. Solve as many as MCQs for your practice 

Try to overcome your weakness. 

In order to score good marks in your exam you should practice a lot. work on your time management. solve as many as mock test series for your practice. 

Be determined and self motivated to crack your exam

All the Best!!

Friend, the best time to change your future prospects and increase your success opportunities is the time in which your are currently experiencing. Boards are important as they showcase your hard work but still I suggest you to put more time in jee as it is the only way to the great colleges of India. My experience,  I would share with you to get an idea. I gave 8 hours to jee mains and 5 hours to boards and still got a good rank. So start working hard and give very less time to any other activities than studies for some few months. Tough days today will make your best tomorrow.