Dear student,

Since only 15 days are Left, so you can do Read ncert but only for inorganic chemistry.

Now, only 15 days are remaining so, you have to revise in a good manner with all the important questions, key concepts, etc. then it is best to revise notes and practice the sample papers and the previous years question papers. Because there is very less time. Revise and practice as much as you can do. And revise only those concepts which you find difficult or you get stuck while solving problems. And solve the previous 10 years questions papers of jee mains atleast 5 times.

So, it will be best to revise notes or lectures and practice questions.