hi ramesh

if you could recall, while registering for colleges, they will be asking various details of you like, name, fathers name, DOB, phone number, mail iD.

yeah, MAIL ID. if you lost phone number, then you can give forgot password and get a verification mail, then change the password.

if this doesnt work, then contact your Service provider and get a new sim with same number. you have to make some validation for this.

these are some methods that might work.

i hope it helps you