Hello there,

It is not that hard to score 92 to 93 percentile in jee mains 2021 even if you start studying even now with full dedication and discipline. If you calculate you have approx. 3 months left for Jan attempt so you may divide the chapters into three categories of strong, moderate and weak and then try to keep your moderate chapters section empty, either know the complete chapter or know very little about it having moderate knowledge of chapter is very dangerous and will prove to time consuming while attempting questions.

Make week wise time table and set targets weekly and then monthly. make sure that after a week completes you complete the decided chapters and do give mock tests as much as you can they help you know where you stand and how much you need to improve.
Focus more on 12th class chapters and study according to previous year's chapter weightage. From class 11 focus on those chapters that have high weightage and are easy to do.
Practice maths!!
be thorough with physics formulas

with this i am sure u can easily score around 92-93 percentile.

Hope it helps
ALL THE BEST!