The journey from Kohima to Dhanbad is a 1000 km trip. The most practical route is to travel from Kohima to Dimapur, then take a direct train to Dhanbad. This route connects the Northeast to the coal capital of India.
Total Distance: 1000 km by rail; 700 km straight-line.
Check for direct trains like the Brahmaputra Mail or similar.
October to March for pleasant weather.