 On 1 April 1964, he was granted a permanent commission in the regular Indian Army with the rank of second lieutenant (seniority from 21 August 1962), and relinquished his commission in the Jammu and Kashmir Militia.He was promoted to lieutenant on 21 August 1964.In the Indo-Pakistani War of 1971, Rinchen, now a major in the Ladakh Scouts, led the capture of the Chalunka complex of the Pakistani Army and the strategic outpost of Turtuk.