India has only one time zone, which is 5:30 + GMT (or 9 hours, 30 minutes difference from New York).
Hindi is the major language, however, nearly 400 different tongues are spoken in the land. English is spoken by your guides, plus in most tourist hotels. English is also fairly well known, at least in slight degrees, in larger cities, by many people, especially the well-educated.
The local currency is the Indian rupee. The current exchange rate is approximately 50 Indian rupees to one US dollar. On November 8, 2016, India demonetized 500 and 1,000 rupee notes, which are now illegal to carry. Most hotels and many restaurants accept major credit cards. ATMs are widely available in larger towns.
Eletricity runs on 220 volts so a voltage adapter may be required. Many electronics include the adapter in the power cords, so before you buy one, check to see if you really need one. Be sure, however, to bring a plug adapter kit, available at a local travel store, some hardware stores, some big box stores, or online. Many deluxe hotels provide hair dryers but you should bring your own if you use one regularly.
The international dialling code for Delhi is +91 11.