It is highly unlikely for an email not to work. Neverthless, if you do not have a functional email id, it is a problem because all the communication from VIT will happen at your registered email and mobile number. So to be honest, retrieving your application number without your email id might be difficult because the details will be sent to your email id . Please reach out to the helpline at: 0416-2202125 and 0416-3305555