Hello Aspirant,

Since you have not mentioned the name of examination for which you want to retrieve your User ID and Password so it is quite difficult for us to guide you with an accurate information but commonly if you register for any entrance examination or competitive examination the User ID or Registration number is sent to your registered mobile number through SMS and also on the e-mail ID of candidate so you can check those once and for Password you can use Forgot Password option through which you can either generate a new password or you can also get that old password depending upon the algorithm of authority.

I hope this information helps you, if not then kindly help us with the exact name of application.

Good Luck!!