It is a must. For all the Chaos that prevails, trains and busses run on time through most of India. Transportation is no problem at all. The overnight train is the best way to travel. Culture, Customs and Communication Through most of South India you can get away with just knowing English.
Most people can speak English or even just understand the basics.
People are very tolerant but when you go to a temple or church or mosque remember that your legs have to be covered fully. So wear a pant or a skirt that hits the ground. This is a 3-week Itinerary that can be shortened or stretched according to your time restrictions. There are hundreds of hotels to choose from, everything from 5 star to budget motels. In Madras you can take the local Autos which are three wheel taxis all round town.