To reach Gangtok from Diphu, you must first travel to Guwahati. From Guwahati, you can take a train to New Jalpaiguri (NJP) near Siliguri. From NJP, you can take a taxi or bus to Gangtok. Gangtok is a beautiful hill station in the Himalayas.
Total Distance: 600 km by road, 450 km air distance.
The road from Siliguri to Gangtok is scenic but winding.
March to June and September to December.