Greetings Aryan!

Hope you're doing great.

No need to upload OBC-NCL certificate again. You can simply keep the documents safe until you pass through the CSAB process. Your admission to the college will be based on document verification, you can show the same at that time. It seems that they had accepted the documents or else they would have let you know.

Similarly, for the jee advance as well. If they ask for any sort of rectification then do it else, you can just keep as it is.

Hope this will help. Do reach out in the comment section below if you need any help.

Cheers!