Dear aspirant !

Hope you are doing well ! This is the same problem faced by many students Every year ,but you should not be worry about it . See firstly look at your marksheet ,there will be school name even if you are a private candidate ,and also there will be a code in topmost corner of marksheet that is school code contain 6 digits  that is to be filled in jee mains form of first attempt.

Hope it helps you !

Thanking you