Ok i will relate your question to my experience.
It doesn't matter from which college you have completed your respective year, those colleges should be affiliated to Mumbai University which is very obvious.
Mumbai University attest it and put it in a sealed envelope.
Few tips:-
1. Stay there for whole day and tell them to attest it today as i need very urgently or you can use any tool to motivate them
2. Ask them how much time they will take to send your application to WES? if they take time, then take sealed envelope from them, put your marksheets and degrees and send by yourself.
off topic- If anyone will say that university has to send it and applicant can't send it, then paste wes link on their faces and tell them to read. I am serious, people are so confused as they send bachelors with masters WHYYYY?
i send my masters to WES on 6th march and i got it yesterday, simple and to the point