Hello,

Okay you want to appear next year in JEE Mains. Which is a big decision because you want to drop one year. Think twice dear, because if you want to join engineering then after completing your BTech you have not appear so many companies because of your education gap. Because in placement so many companies wants fresh candidate not a candidate including gap. So this is a huge problem I'll tell you.

Now if you determine that you want to go for drop and get very good marks and join NITs or IITs or very good government college then you can apply for 2nd time. For this reason you have to study all your NCERT books for mathematics physics and chemistry. You can download the syllabus and print out and marks it whenever your chapter is completed. Then you can go study by yourself self also. But remember every time note down the important thing. You can join coaching classes but you have to study by yourself. Otherwise you can't get good marks. You can give mocktest. You can practice previous year question. I'll provide you a link below you can check it for more details about the mocktest

https://learn.careers360.com/test-series-jee-main-free-mock-test/

All the best.