Hello,

It is good thing that you want to do aerospace or aeronautical engineering. Both are same. You want to join IIT for which you have to qualify jee advance with decent marks and rank.

for IIT bombay which is the top #1 IIT in India the cutoff rank was 2082 for general.You can see how competitive it is.

About learning,practice is the only way to make this possible. Try to solve as much numericals by understanfding the problem you can and learn them. If you do just you have to do then you will forget it and get confused in the exam even you get the same question.

There are many sites who provide different courses. You can look for them in web.

Here are some tips:- https://engineering.careers360.com/articles/jee-advanced-preparation-tips-physics-chemistry-and-mathematics

follow it and learn all the time. Solving numericals is the only to make you bring confidence that you can solve any problem given to you.

Hope it helps!