I read a post dated January 2017 by dhanushmenon on team-bhp.com . The route is Bomdila to Rupa to Shergaon to Kalaktang to Amatulla to Mazbot to Orang to Rowta to Mangaldoi to Sipajhar to Guwahati- total distance 310 kms. There is supposed to be very little traffic on this road.
Is there any decent hotel at Shergaon or Kalaktang?
I intend taking this route on my return journey from Tawang to Guwahati in middle April 2018