hey krishna,

Your email id is the username and if you forget your password then go click the forget password option, Enter the email address you originally used to create a CET login. After you enter your email and select Reset Password, you will receive an email within one hour with instructions to change your password. Please check your spam inbox if you do not receive an automated email. If you use your CET to login, you will not be able to reset your password in this manner.

Hope that helps 

All the best