The four key conditions that enable a Tornado are: • Moisture in the lower to mid levels of the atmosphere. • Unstable air. That is, air that will continue rising once it begins rising from near the ground. • A lifting force. read more
You can't say that they don't occur in India at all. In fact in the past and as others in this thread have pointed out, there have been some tornadoes in India (although reports aren't that confirmed like they are in USA because of issues like lack of doppler radars and storm spotting network). read more
Tornadoes can occur anywhere as long as the atmospheric conditions are right. They are most common in the temperate zone (North India is in that zone, above the Tropic of Cancer) where warm air from the south comes in contact with cool air from the north. read more
Although tornadoes occur in many parts of the world, these destructive forces of nature are found most frequently in the United States east of the Rocky Mountains during the spring and summer months. In an average year, 800 tornadoes are reported nationwide, resulting in 80 deaths and over 1,500 injuries. read more