The journey from Amritsar to Guwahati is very long, covering 2300 km. There are no direct trains, so you will need to change at major hubs. Flights are the most practical option, usually with a layover in Delhi or Kolkata. Guwahati is the gateway to Northeast India.
Total Distance: 2300 km by road, 1900 km by air.
Very long journey, plan accordingly.
October to March.