Each day is crucial if you are preparing for a good rank in Jee, but the most crucial time where you have to focus a lot is the time 3 months before Jee mains. At this time, you have to focus on revision and your ongoing syllabus. Also, you have to start solving complete syllabus mock tests and pyqs and have to focus on some weaknesses.

So my advice is if you want minor weaknesses, don't waste your single day and make short notes so that you revise concepts in less time and in a more effective way, and you won't feel pressurized during this crucial period.

All the best 👍 👍👍.