You have to check with local authorities to find out the process of issuing a new copy.
@armoured 's post above covers the topic in detail.
If the one you currently have says Bombay then I assume the document is older than 1995. In that case I'd suggest getting a new copy if that process is easy.
But if the process is crazy long (6 months) then apply for the new copy anyways but submit your sponsorship application with the old one and include a letter of explanation about that it's old and it will take you 6 months to get a new copy. Mention to them that if IRCC wants the new copy they can let you know and you can provide it later when it arrives.
Note this second option might be over complicating a simple situation. It's your call.