Cruise lines offer wide variety of foods from around the globe, but many cruise line offer most of the time the specific food of the country that it is sailing. You can most likely find some type of Indian food on your next cruise, not matter what cruise line you go on. Indian food is a commonly found in almost all cruise lines.
On Royal Caribbean ships main buffet Windjammer Cafes serves the Indian food most of the times. Royal Caribbean may offer one of the day only Indian food as indian dinner night. Royal Caribbean serves both vegetarian and non vegetarian dishes , and if you don’t see it and crave for it then you can request the manager on duty and they might arrange the food for you. Most of the times during buffet they have live station for making stir fry of your selected choice of meat/vegetables or sauce/spices.