Dear Student,

With 72% marks in marks it is difficult for you to come in top 20% . 72 percent is not a bad score . If you want to take drop for JEE Mains then you can take drop easily. And there you must have to study very hard to get a good score in both JEE and 12th.

In my opinion you must take the drop for JEE and alongwith that you must fill the 12th improvement form . When you will be preparing for JEE then automatically your 12th boards syllabus will cover up. And when your boards exam come next year , you will have to perform very good. And also you can give JEE Mains and Advance the same year. By this you will cover both 12th and JEE in a single year .

Hope this helps.