Gangtok being one of the most eminent Buddhist pilgrimage centres and also a popular hill station, has a well connected air, road and rail network. Best way of travelling to this place would be, taking a flight to Bagdogra Airport. The distance between Bagdogra and Gangtok is 124 kms. On reaching, you can easily hire a shared taxi or a private vehicle which will get you to Gangtok in no less time.
Looking forward to a journey by train? New Jalpaiguri is the closest railway station to Gangtok. New Jalpaiguri is around 117 kms from Gangtok. You can easily take a train till New Jalpaiguri, and on getting down, you can further take a shared jeep or hire a private taxi to reach Gangtok. New Jalpaiguri is a major railway junction which is well linked with numerous cities across India.
If you wish to take a plane to reach Gangtok, then the nearest airport will be Bagdogra, West Bengal. It is around 124 kms away from Gangtok ans is a major airport which is well connected and has frequent flights operating to and from most popular cities across India. On reaching the airport, one can hire a cab or a private vehicle to reach Gangtok, which will take around 4 - 5 hours.
Siliguri is the place from where one can take a public bus, shared or a private taxi to reach Gangtok. If you plan to take the roads, the distance between Siliguri and Gangtok is around 114 kms which can be covered by road.