In Born In Tibet Rinpoche describes the aircraft in which he flew from Tuting village on to the Indian plains as used for cargo. It was almost certainly a Douglas C-47 Dakota of the Indian Air Force, which used it as its main transport aircraft for four decades from the end of WWII. It would have been used mainly to supply the small military garrison whose commander so generously hosted Rinpoche after his arrival in India.
Affectionately named the "Gooney Bird" by US pilots, it was known in British Commonwealth countries as the Dakota and, in its civilian version, as the famous DC-3 -- widely recognized as the most successful passenger plane ever flown. Designed in 1934, over 2,000 aircraft still provide good service around the world today.