How to get in good batches in kota in Allen or any other institutes?

So I will be taking a drop and going to kota, you can suggest me sm good institutes for JEE prep.

My main question is how do I get into top batches in these good institutes as a dropper. I mean do they have tests during their initial months for droppers as my prep is fucked up currently. Does batch reshuffling even for droppers exist?