In order to score good marks in your boards exam make sure your concepts are clear. Complete your NCERT books throughly. 

You can also make your time-table according to your comfort and make sure you follow it. 

You can set your time-table according to your strength and weakness. 

You should give importance to the chapters which carries more weightage in the exam. 

You can refer previous year papers to understand the exam pattern and to know the level of the questions asked in the exam.

It is very important that you clear all your doubts. You can take help of teachers or you can also join study groups.

All the best for your boards exam!!