Hello Surovi
I think you are asking about the jee mains.
Yes you can do this if you think that you can secure 100 + marks in 2 subjects.
But one thing I tell you that it will take more hard work to increase your score in one subject after a level than to increase your score in other subject upto that average score .
And you can not depend upon only 2 subjects beacause this exam will decide your future admission.( If out of these two subjects one subject will be calculative and time consuming than if you are prepared with third subject you can attempt third subject and cover that calculative subject).
So I would suggest you to go through all the subjects ( because it will also help you in future and in college also.)
But atlast it is your decision .
Good luck