India's major domestic airline, the government-run Indian Airlines, has an extensive network. The country's international carrier, Air India, also operates domestically on the Mumbai (Bombay)-Delhi, Mumbai-Calcutta, Delhi-Calcutta and Mumbai-Chennai (Madras) routes. Deregulation has radically improved service and swollen the number of secondary operators, though several have gone belly up recently. Sahara Indian Airlines and Jet Airways are probably the most stable of the new competitors.
The Indian Railways system is deservedly legendary and Indian rail travel is unlike any other sort of travel on earth. At times rail travel can be uncomfortable and frustrating, but it is also an integral part of the Indian travel experience. You should try to pick up the key points of Indian train etiquette as quickly as possible, otherwise you'll find yourself hopelessly attempting to defend your own private space. There are a number of different classes and a number of different trains: you want express or mail trains, but try all the different classes just for the hell of it. The Indian reservation system is labyrinthine and worthy of anthropological study, but be patient because it's one of the few bureaucracies in the country that actually works. When booking tickets, take advantage of the tourist quota allotment if one exists. You'll find it easier to reserve a seat this way.
Buses vary widely from state to state, but there is often a choice of buses on the main routes - ordinary, express, semi-luxe, deluxe, deluxe air-con and even deluxe sleeper. Government buses are supplemented by private operators on many routes. Private buses tend to be faster, more expensive and more comfortable and can make a lot of sense on longer jaunts. Bus travel is generally crowded, cramped, slow and uncomfortable. This is the good news. The bad news is the rugby scrum you often need to negotiate in order to board, and the howling Hindi pop music which blares from the tinny speakers. Buses are the only way to get to Kashmir and the best way to get to Nepal from Uttar Pradesh; they are generally faster than trains in northern Bihar and in large areas of Rajasthan.
You can hire a car and driver very easily, but you need nerves of steel and excellent karma to consider driving yourself. Cars are usually rented on a daily basis and come with a limited number of km per day. You'll probably be responsible for the driver's expenses, so be sure to clarify how much this is to be each day before you set off. If you're planning a long trip, it's wise to go for a short spin with your prospective driver just in case you don't like his braking ability.
Motorcycling around India (especially on an Enfield Bullet) has become a popular pastime, though it's a hazardous endeavour and not for the amateur two-wheeler. Bicycles are a great way to get around towns and can usually be hired for a pittance. Long-distance touring, however, is not for the faint-hearted or the weak of knee. If you're thinking of bringing your own bike, think twice about bringing your state-of-the-art 10-speed unless you want it to be poked, probed and perved at every time you stop.
Local transport includes buses, taxis, auto-rickshaws, cycle-rickshaws and tongas (horse-drawn carriages). Taxis may have meters, but don't expect them to be working in more than a handful of cities. Three-wheeled auto-rickshaws are generally half the price of a taxi and allow much better passenger inhalation of diesel fumes. Cycle-rickshaws have all but disappeared from the centres of major Indian cities but are still an essential part of the transport network in smaller towns. Be sure to agree on a fare beforehand.