For low calorie Indian foods, the easiest way to cut calories is to cut the rice. Ask for curries/kormas with lean meat like chicken and bulked out with veggies. Instead of eating them over rice, just eat the main dish with the meat/veg and sauce. You could also order a side vegetable and pour it over that instead, in some restaurants.
Also, look for tikka and tandoori style cooked foods which are grilled or oven baked rather than fried/sauteed, as they tend to use less oil. Try to avoid dishes that include coconut, cream, or ghee as these are automatically going to be higher in fat. You can also skip the naan, or limit yourself to one bread. (Here's another option for skipping the rice--dip your naan in the meal or even top your naan with it and roll it up like a tortilla. You may get some odd looks, but, hey, you'll save calories on the rice.
Further, most Indian restaurants I have been in are happy to accommodate some western tastes. If you want to go ahead and ask the waiter, could he suggest a lighter option, or could he ask the chef to leave off the oil/cream/etc, you may be surprised by how accommodating they will be.
I also second the yogurt/fruit idea above. Find out what the locals are eating for breakfast or healthy, light meals. In Ukraine, we would regularly have 'drinking yogurt' and fruit for breakfast. It ended up being one of my favorite meals and I used to search for that liquid yogurt when I got back to the US.
If all else fails, simply limit the amount you eat. Why not order one meal and share it between two?
