Born in Pudukottai, Shanmugasundaram was very eager to join cinema though he held a bachelor's degree in mathematics from Madras University.
Instead, while working at Raj Bhavan Guindy Chennai, he tried his luck in cinema knocking on the doors of every film company to earn a better income.
At long last, his relentless efforts yielded result by getting him the opportunity to enter cinema through the film Aayiram Kaalathu Payiru in which he was introduced as "Raja B.A.".
[2] Rajan acted in a movie produced by AVM Productions called Naanum Oru Penn, a film that starred S.S.Rajendran in the lead role.
On 19 January 1984,[3] through a personal encounter with God, Rajan converted and there after became a full-time Christian preacher since 1988[4] and since then has stopped acting in movies and dramas.