Chicken tikka's not a bad idea (no, not the masala

). But seriously, Indian restaurants cook an awful lot in ghee which, while yummy, is also about as fatty as fats get

100g of ghee is over 900 calories.
Try to stick with things which are baked rather than fried, such as Tandori meats (again, ensure you're not ordering a Tandori + sauce such as a Tandori Masala, as most of the lower-heat sauces have a lot of cream in them). Try also to avoid breads (including poppadoms, nan, chapati, etc) and paneer (which is also lovely because of its yummy cheesy fat).
If you need sauce (oo-err) go for something more tomato-based like a Rogan Josh. Try to stick with chicken, as beef and lamb are fattier. The
average Indian restaurant's Chicken Rogan Josh is about 550-600 calories. Madras is another tomato-based sauce, which comes in at around 600 calories (don't forget these are excluding the rice).
Try also to just avoid anything fried (Samosa, bhaji, etc). That's common sense. I'd also, alas, avoid the mango chutney. It can come in between 25-40 calories for a tablespoon, and you'll get through a lot more than that with a whole poppadom (itself around 50-60 calories).
Finally, if possible, eat something before you go. A salad, some fruit, something that means you're more likely to leave food on your plate at the restaurant. A hundred calories of salad at home could save you 400 calories there. That way you've done the polite thing of turning up,
and you're not leaving hungry because you're worried about the calories.