The journey from Malappuram to Guwahati is a massive 3000 km trek across the length of India. The most practical way is to take a train to Kolkata and then a connecting train to Guwahati. Alternatively, flying is highly recommended due to the extreme distance. Guwahati is the gateway to the Northeast and a major hub for tourism.
Total Distance: 3000 km by road and 2500 km air distance.
This is a very long journey; consider breaking it up.
October to April for pleasant weather.