See if you are really up to pursue engineering from NIT's or IIT's and you are seriously motivated about it then going for a drop year can be of good use. During your drop year, you should be very disciplined and you should make a good use of the time. Learning only the theories may not be of great use but practicing problems and increasing your accuracy is most important. Also if you are up for a drop year, then going for a good guidance can be of great use. So join some mentor/ coaching institute so that you can use there experience for a successful result ahead. Also, giving the mock examinations should also be your prime concern. If you can take this features, then you will surely do great in the JEE 2023.

For JEE MAINS preparation tips consider the link below:

https://engineering.careers360.com/articles/how-prepare-for-jee-main

I hope this helps. Goodnight!