If your JEE is a few months away

1. Make a list of your weak topics(and weak sections of a topic too).
2. Pick up very basic material from your coaching and clear those topics first, no fancy stuff at all for now. Your first Target is JEE(Main) and syllabus completion is more important than solving tough questions.
3. Take out some time on a daily basis for revising Inorganic and Organic chemistry, because that is the part which will help you the most on the exam day, and it requires immense revision.
4. Start solving some good questions(i.e. of JEE(Advanced) from topics you are confident in(only after you have completed your daily tasks pertaining to points 1,2, and 3).
5. Note down your daily and weekly targets somewhere before going to bed. Try to keep it 10% more than what is really possible for you and try to complete it everyday.
6. Note down your doubts somewhere and get them cleared as soon as possible.
7. Start studying your language and fifth subject, because you need to secure good marks in boards too.
8. Start studying NCERT whenever you get time. It will prepare you for both Boards and JEE (specially chemistry).
9. Take good care of your health.
10. Stop wasting time. If you waste time now, you are doomed. And if you are doomed already, this time can take you out of it.

If your JEE is >1 year away

1. Your school and coaching classes would be giving you at least one month break. Clear your backlogs.
2. Follow points 1,2,3,5,6 for class 11 syllabus.
3. If you missed a chapter in 11th, now is a good time to study it.
4. Basically, make sure that you cover as many important chapters as possible before you step into 12th.
5. Get ready for the most important year in your life until now.
6. Now is a good time to stop b...