There are many possible reasons due to which your name is not shown. some of them, I am mentioning here;
1. First tell me, did you receive your first sem payment? If not, you may not register at that college or your joining report has not been uploaded.
2. Your college may discontinue you at the AICTE Portal. This may also be a reason.
3. It can also be a technical issue on the AICTE portal that will be resolved soon.
So, explain briefly, what is your problem?