[2] For a year he worked as a Rationing Officer[2] with the Government of Tamil Nadu (erstwhile Government of Madras) before proceeding for spiritual studies at the United Theological College, Bangalore during the years 1952-1955[3] where he studied along with E. C. John, Victor Premasagar, N. D. Ananda Rao Samuel and others.
[4] In 1964 Jathanna got a scholarship of the Mission-Academy and went on study leave to the University of Hamburg, Hamburg where he studied Old Testament at the Faculty of Evangelical Theology under Klaus Koch, a direct student of Gerhard von Rad.
[2] From 1959 onwards Jathanna was assigned a pastoral role and served as an evangelist before his ordination in 1960.
[2] After completing doctoral studies in 1967,[2] he was appointed principal of the Karnataka Theological College, Mangalore.
In 1980, Jathanna visited the Andhra Christian Theological College, Hyderabad along with Klaus Koch (who was visiting professor at the United Theological College, Bangalore as part of the research committee of the Senate.