The journey from Piplod to Gangtok covers approximately 2000 km. You should reach Dahod station, take a train to New Jalpaiguri, and then travel by road to Gangtok. Expect a travel time of 40+ hours.
Total Distance: 2000 km by road, 1700 km straight-line.
Book a taxi from New Jalpaiguri to Gangtok.
March to June for pleasant weather.