Take the ring you don't need to wear it.
Most jewelers will weigh the gold and check if it is 9, 18 or 24 carat and then either give you an allowance or if it is big enough will be happy to make something up for you.
Most gold sold in Goa is 18 carat, 24 carat is about 1,000 rps per gram.
If you walk towards Candolim from your hotel there is a small Jewelers called Lala Arts on the left hand side of the road nearly opposite the school.
Ask for Dagga (you can't miss him he has blue eyes and brown hair, his brother has brown eyes and black hair).
Also Pop In Jewelers on beach road in Candolim, just up from the Inferno.
Both will be happy to take something and remodel it.
When you go into a jewelers you will often be offered a drink, tea (Kashmir) or a cold drink. Don't be afraid of accepting even if you buy nothing they will be ok.