Sevrin embarked on an educational career, first as a teacher in the St. John's High School in Ranchi and later as inspector of the Catholic missions schools in the whole area when, to everybody’s surprise, he was appointed bishop of Ranchi. The diocese had been created in 1927 and Sevrin was its second bishop. Education remained a priority and he did much to develop an educational network for the Mundas, Oraons and Kharias in the vast area covered by the diocese. He promoted also the local press by creating the Hindi language magazine called Nishkalanka and composed a little catechism and other booklets in order to build up a faith culture among the many new Christians of his diocese.
Bishop of Raigarh-Ambikapur (Chhattisgarh)
In 1951 something quite unusual happened: Sevrin, at the age of 67, asked Pope Pius XII the permission to be relieved from his responsibility in Ranchi. He was giving two reasons: there was a local Oraon priest, Nicolas Kujur, who, Sevrin felt, was quite capable of taking his place as the pastor of the diocese, and, second, he wanted to go to a neighbouring state where conditions of missionary work – because of great hostility towards Christianity – were extremely difficult. His new diocese, Raigarh-Ambikapur, was formed of several little princely states where, as long as they were autonomous, the presence of Christian missionaries was strictly prohibited. Illiteracy and the exploitation of the tribal people were rife. Sevrin, the new bishop, settled down in a small parish and started his work: education, medical help, economic and social development were going hand in hand with evangelization. Success got him many enemies and he had to face a number of malefide court cases. On the other hand, he acquired great prestige among the aboriginal population of the area, including non-Christians. He was highly esteemed. In 1957, for the second time, he decided to resign to allow a local man to be the religious leader of his own people. Sevrin ordained bishop his own successor at Raigarh-Ambikapur: Stanislas Tigga. This did not mean retirement, however. Appointed spiritual guide and professor of religion in the high school of Kunkuri he remained active till his death at the age of 91 on 30 April 1975 in Kunkuri, Chhattisgarh, India.