To date, the official currency of India is the rupee (INR). Going on vacation in this country, it is better, yet take with them dollars, not euros. The rate when exchanging USD for INR is more profitable. It is possible in India to exchange and rubles, but this is in case of emergency.

In order to avoid cheating, it is better to change the currency at the reception in the hotel, at the airport or exchange offices. In general, there are a lot of ATMs in India, so it's much more convenient to have a credit card with you, and less is lost on conversion.