PIN refers to the Postal Index Number. As the name indicates, this number is given by the postal department for indexing a particular area. This code contains 6 digits where each number indicates the district, sub district and so on. The last 2 digits refer to the sorting code of a particular area. For postal code purposes, Sikkim is divided into East Sikkim, Gangtok, North Sikkim, South Sikkim and West Sikkim areas. There are over 50 Pincodes in East Sikkim, 3 in Gangtok, around 20 in North Sikkim, around 30 in South Sikkim and close to 30 codes in West Sikkim area.