If you have not completed your registration process completely then I think you can use a different user id and mobile number. But in case you hav ecompleted your registration and got your user id and password for the SSP portal from ICAI then I don't think that you should register using a different email id and mobile number. Moreover, I don't think using a different email id and mobile number would solve any technical issue that you are facing. You can also email your query to ICAI or call using their helpline number.

Thanks