Prevented from going to Indochina because of unspecified serious events, he was sent to Pondicherry mission. Upon hearing this news, he exclaimed "then the society is afraid to make martyrs." He arrived at Pondicherry on 18 August 1900, and was appointed Professor in
seminar-College, under the strict direction of Father Elisabeth. After three years of service there, in August 1903, he was sent to Tindivanam as assistant to Father Combes. In April 1904, he was sent to Chetpet, as vicar of Father Darras. He was parish priest of Chetpet until 1915. This post at Chetpet really was Father Colas's preferred position. During
World War I French
Mobilization, he had to leave for France in January 1915. He was sent to Salonika. In March 1917, he was demobilised and returned to Pondicherry to regain his post at Chetpet. In 1925, Father Colas was put in charge of the parish at Tindivanam. He was also in-charge of the normal school and the school of catechists at Tindivanam built by Father Gavan Duffy. With financial assistance from Father Gavan Duffy, he managed to finish the beautiful church begun in 1898 by father Combes. ==As a bishop==