Hello,
.
I will let you know few steps for getting back your registration number,
.
1st,
Checkout your maibox or Inbox as you would have received number while the time of registration
.
2nd,
Do visit the website if you ever logined to your account. If you click on username or registration number it will show as suggestion
.
3rd,
Do contact help desk about your problem they will help you to recover it. You can send a mail about your problem.