The journey from Kullu to Chennai is a long 2600 km trip. You must take a bus to Delhi and then a train to Chennai. The train journey from Delhi to Chennai takes about 30-35 hours via the Grand Trunk Express or Tamil Nadu Express. This route connects the Himalayas to the southern coast. Expect a total travel time of 50-60 hours including transfers.
Total Distance: 2600 km by road, 2100 km air distance.
Tamil Nadu Express is a reliable train for this route.
November to February for pleasant weather in Chennai.