Of noble descent, Mochtar was discovered by Albert Balink and first cast in the commercial failure Pareh (1936).

[1] In 1935 Mochtar was cast in the leading role of Mahmud in Albert Balink's film Pareh.

Balink was out with coffee with Joshua and Othniel Wong and saw Mochtar, whom he considered tall, strong, and handsome, driving by.

[3] According to the Indonesian anthropologist Albertus Budi Susanto, the emphasis on Mochtar's title was meant as a way to draw a higher-class audience.

[8] After the success of Terang Boelan and Balink's emigration to the United States, most of the cast – including Mochtar – were signed with Tan's Film.

[10] During the Japanese occupation (1942–1945) and ensuing four-year revolution, Mochtar acted in several theatrical groups, including Terang Boelan, Bintang Soerabaja, and Pantai Warna.

Aside from Indonesian films, he also had a role in Rodrigo de Villa, by the Philippine company LVN Pictures.