Hello ANshit,

The study plan is simple, find out the syllabus for the exam and start preparaing.

Consider good books, lay emphais on NCERT, plan a work schedule, you may conside preparing a check list abou the topics and then cut as soon as you complete it. Also prepare by solving previous year papers. Solve, analyse the paper and then again solve till you get 100% score in that particular paper.

If preparing for NIT, then find the cut-off here, and then set that score as your target. Find the topics wise weightage and prepare on the topics that you think are enough to clear that cut-off.

https://engineering.careers360.com/articles/jee-main-cutoff-for-top-nits

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

Hope this helps