The journey from Malappuram to Dehradun is a massive 2900 km trek across the length of India. The most practical way is to take a train to New Delhi and then a connecting train to Dehradun. Alternatively, flying is highly recommended due to the extreme distance. Dehradun is a beautiful city in the foothills of the Himalayas.
Total Distance: 2900 km by road and 2400 km air distance.
This is a very long journey; consider breaking it up.
March to June and September to November.