The Sikh Families of Assam
It seems that he went along on a trip with a transport contractor for the army all the way to Assam, and then simply began driving trucks. That his own uncle (chacha) was already working here in Tezpur, also driving trucks, would have helped. After working for a few years as a driver, he started a small kirana/gelamaal (grocery) shop in Tenga Valley in Arunachal Pradesh. He also founded a hotel that ran for around seven years. Eventually he got around to buying some trucks and built a transport business for himself - a few contracts with the Indian Army hastened the cause.