Hello dear ,

If you want to crack  JEE mains with one or two subjects Your score  will be 100 + . If you are Good at some particular subject you can focus on it well to score good marks . If you get at least 70 in each each you can easily get admission in good colleges . you can study any subject you are interested in .

I hope this helps you !

Hello aspirant

Yes, you can study well or can concentrate more on your subject of interest . If your maths is strong and you are weak in physics , you must prepare all the important chapters of maths very well. In chemistry subject organic chemistry is found interesting by most of students ,then practice those topics  if you also find it interesting.

While preparing for physics , you can prepare most important chapters and can skip the topics you find difficult to understand. Clear the concept of all the covered topics . Revise them again and again.