Visvesvaraya Technological University — USN 1BI09IS046 - EDDTS unable to change registered mobile no.

My USN is 1BI09IS046 & I was trying to Sign up to EDDTS website with a US mobile no. which looks like isn't supported since I got error "Incorrect mobile no."

Now when I try to Sign up with an Indian mobile no., I get an error saying "USN is already registered". So I'm stuck trying to receive an OTP on my US number and I don't see an option of changing the registered mobile no.

I need urgent help with this.