He was appointed as the acting head of the Agam Underdistrict on 8 October 1945, a week after the formation of the West Sumatra Government.

[4] Aside from his position in the bureaucracy, Djosan was also involved with negotiations between the Indonesian and the Dutch forces in early January 1947.

During this period, Djosan oversaw interfaith discussion between Muslims and Christians in the region[6] as well as the replacement of the regent of Central Maluku.

Several names, such as Pieter Andreas de Queljoe, Mohammad Padang, and dr. Rehatta were nominated to become the definitive governor.

Djosan also initiated the establishment of NU branch in Ambon, the capital of Maluku, which provoked further resentment from Masyumi and Parkindo.

[20] In response to the criticism, the interior minister stated that Djosan was "upright, competent and experienced in administrative matters" and "dare to act and take the initiative".