Poisson Cru is a Tahitian dish very much popular among tourists, which is made from raw marinated fish dipped in coconut milk and lime juice along with some veggies. Most of the restaurants include this super-tasty dish in their menus. Imported foods cost terribly high, so prefer local Polynesian food to save your pocket.
You can't expect Indian cuisine to be served in French Polynesia. Most of the dishes are prepared with seafood or meat, so vegetarian food is a little hard to find. Restaurants at InterContinental Resorts, The Lagoon Restaurant and Le Bounty Restaurant notedly offer veg options. It is recommended to send a mail to the chef/restaurant requesting about your eating preferences beforehand, so that they can arrange the things for you in advance. Bring along some dry snacks with you.