If you are flying internationally, it might be worth looking up the best prices from all international airlines. Skyscanner.co.in looks up all the possible airlines and gets you options for best prices between any two airports. If you are not sure where you wish to go, you can just mention the country and it will show you all the options ! Additionally, it will also suggest the websites where you could book the tickets online.
Be careful when you look at the bare prices though – many a traveller gets attracted by low prices and when he actually books, the taxes may be added. Besides, check out the baggage constraints for each of the flights, since paying for an extra bag will more than make up for the cheap ticket. You may also be paying lower for a flight with multiple stops compared to a non-stop flight. Proceed with caution, but then you have a starting point !