Mar Thomas Tharayil :

 Till his death in 1975 Bishop Thomas Tharayil, the Founder, took personal interest in the spiritual, and apostolic formation of the members as well as in the overall growth and development of the Institute. He gave them spiritual exhortations and classes regularly. He sent a good number of members for professional studies and training in the medical field in India and abroad so that they good effectively discharge the apostolate of the service of the sick. Already in 1957 he let Mary Kalappurakal  take a promise of consecration before him and sent her to Germany for medical graduation in view of  her later service in India as a member of Institute.

The following houses were started during the episcopate of Bishop Tharayil,

 Caritas Secular Institute Thellakom,Caritas Polytechnic School for Girls Mannamala,and Mercy Bhavan Alex Nagar  .