• Be a master in simplification and calculation of maths problems.
• Practice a lot of problems.
• Be crystal clear with the fundamental concepts.
• Try to study longer duration of time.
• Make a timetable and live upto it.
• Join a good coaching center.

Hello student. It is really good that you have started the preperation really soon. If the preperation is one in the right way, then definitely, you would be getting good iits with the branch you desire.

So for that, the first thing is, you need to know the syllabus. Of jee mains and advanced. 11th and 12th syllabus the updated one.

This preperation should be in parallel with your regular 9th or 10th curriculum. Don't lose concentration over that. 10th is important too.

In this case, I suggest to go to the best coaching institute near you. Because, you can prepare the theory , but certain tricks and tips, place, speed, familiarity etc all these needed from outside .

So get ncert books of 11th and 12th and start working out the concepts. Try remember theory from chemistry. Solving sums of level 1 and level 2 in maths and physics.

If you have any cousins, get work books from them and start working on them.

Self study is really difficult

Find a good coaching institute