More than likely, what you have is an Indian star tortoise (Geochelone elegans), not an Australian star. There are no indigenous tortoises in Australia. Here's a link to a good care sheet that will help you with your new tortoise's diet:
I agree, especially considering you're based in Mumbai. I may be wrong, but don't Australians call all chelonia tortoises, even aquatic ones? Remember reading it somewhere but may be wrong. However, I know true torts are illegal to own there and I think it is very hard to get any species out of Australia.