Please contact institute and inform them directly about the same. Once account is approved you will be able to login with your mobile number.

Once you login, you can change the mobile number associated with your account from the edit profile option.
But before login, you will need to inform institute, to assist you with number change.

Although it is rare, but sometimes our server might not send OTP for mobile number verification. In that case, please call the Institute directly. Institute will verify your account and grant access.

Please do wait for some time, after receiving registration request, institute will verify whether you are a student of the institute or not. Once your request is accepted you will receive notification. You can also contact institute directly on call to know about the status.

While trying to login if you see message like "mobile number not found" or "mobile number is not registered", then please ensure that you are using the same mobile number to login which you have registered with institute. 
If the problem still remains, then kindly contact the institute and let them know the problem. Institute will check your registered number and let you know.

If you have recently changed your mobile device, or if you are trying to login to another mobile device, then you can see this message, as you are only allowed to use one device for accessing all your account data.
In case you wish to change your device access, kindly call the institute.