It is mandatory for all foreign nationals have to obtain a special innerline permit for Sikkim which they can get from the Indian Embassy situated in their respective countries. Foreigners can avail only 15 days permit to visit Sikkim which can be renewed. They should be part of a group of minimum 4 persons in order to visit Dzongri (in West Sikkim ) for the purpose of trekking. All the permits can be collected from the Indian Missions in different countries. It can also be collected from Foreigners' Regional Registration Offices in Calcutta , Delhi , Madras & Bombay or the Office of the Assistant Resident Commissioner, Govt. of Sikkim, Calcutta or the office of the Deputy Director (Tourism), Govt. of Sikkim, New Delhi . If you have already come to the region without obtaining proper permits, most travel agencies will assist you in arranging the same from the Assistant Director (Tourism), Govt. of Sikkim, Siliguri or the Deputy Commissioner, Darjeeling . Presently permits can also be obtained from Rangpo at the time of entering Sikkim.