Hi aspirant,
Yoi can check your mail for regeistration number because they generally sent registration number over the mail. Try to check spam folder because it generally go there. However still you not able to find then try to reach helpdesk via contact number or mail id which will be available on website. They will able to assist you further.
hope this is helpful to clear your dilemma.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile