I am afraid my friend you have to visit your college.
This is the process I followed for my ECA assessment:
Step 1: Go to your respective college and ask them for a
transcript as well as collect all the pending marksheets and degree certificate. I believe your college must have them by now.
Step 2: Upload the scanned copies of your marksheets and degree certificate on the IQAS portal and make payment. Make a note of the
File Number as it will be required by Mumbai University.
Step 3: Visit
https://mu.etranscript.in/ (It is the E-attestation portal of Mumbai University) and create an account and follow the steps mentioned there.
Step 4: The MU has a secured direct digital channel for transmitting transcripts to IQAS. They will just need your File Number and then after all this you can track your transcripts through the MU e-attestation dashboard.
The Mumbai University has done a commendable job on this.
Hope this helps.