I dont know about Mumbai,but In islamabad they will not accept anything other than original copies of certified copies of the sposnors passport which shows their current status. It is a possibility thats its the same in Mumbai.
My advise to you is to have a few pages of your passport cerified by a solicitor ( the bit where it shows your name and photo + the page showing your status in the UK)and post them to Mumbai with an explanatory note ( dont forget to give name DOB , address of your parents that you have sponsored).
You must do it quiickly, because it might be to late if they refuse your parents visa because they have not provided details of your status in the uK
Here is teh address
Naman Chambers,
C/32 G Block Bandra Kurla Complex,
Bandra (East) Mumbai 400 051
VFS Office in Mumbai
Telephone:
(91) (22) 66502222
Emergency Duty officer: (91) (0) 98200 00343
Please note that this number is for emergencies pertaining to British Nationals only. Queries of any other kind will not be entertained.
Fax: (91) (22) 66502324
Email:
postmaster.bomba@fco.gov.uk
Website:
http://ukinindia.fco.gov.uk
Office hours:
Mon - Thurs: 08.30 - 13.30
Fridays: 08.30 - 12.30
Mon - Fri: 0830 - 1330 (Consular)