Hi bro, so after you paid for your application fees a mail will be sent to your mail id what you gave in application form, the mail is for you to complete your enrollment, so basically before entrance exams itself they will ask you to complete enrollment you need to fill all the things that are required and upload it.
so, after the entrance exams if you meet the eligibility they move your application to next step where they ask you to pay your fees, after that your are a student of srm.
To do your enrollment a link will be attached in that mail with username and password so you need to login in that website and complete your enrollment process so if you need any information regarding that it will attached in that mail. any other doubts regarding admission you can ask me. hope you found the solution.