Dear Sumit,

I have come across Alakh Pandey Sir's lectures, and they are really good with clear explanations on the topics.

But, I would like to add that nothing is enough until you dedicate huge number of hours into self study. There are plenty of recommended books by H.C Verma, O.P.Tandon and RD Sharma. You can go through them. Also multiple revisions and practice of MCQs and solving last year questions are highly recommended.

Self study is the only key to success!

I wish you all the very best and hope to see you in some IIT soon!