Dear aspirant,

For JEE main preparation, make sure you go through your NCERT and reference books thoroughly.

1. Chemistry - P Bahadur for physical chemistry, OP Tandon for Organic and NCERT for inorganic chemistry.

2. Physics - HC Verma and NCERT

3. Math - Cengage publication books.

You can self study very well with these books and then take test series of some reputed institution like Allen. They offer topic wise regular test series for you check your progress. If you want to get a full on online course package, you can try the course package of Vedantu, Unacademy ATP Star etc.They offer JEE mains preparation packages for droppers.  But I would strongly recommend self-study + practice regularly + clarify your doubts with your teachers

Hope this helps

Hope this