Sujatha ( S.Rangarajan) was born in Triplicane, Chennai but spent his childhood in Srirangam near Tiruchirapalli under the care of his paternal grandmother.  Rangarajan attended school in Srirangam Boys higher secondary school. He did his under graduation in physics in St.Joseph's College, Trichy where he was the classmate of President Abdul Kalam. Later on, he did his engineering in electronics at the Madras Institute of Technology.

His writing interests were largely inspired by the short stories and serials published in Popular Tamil Magazines and literary magazines... "Sriranganthu Devathigal" (Angels of Srirangam) was a famous series based on the real llife in that town the 50’s. His first short stories appeared in Kumudham “Paalam" (bridge) in Anandha Vikatan attracted reader’s attention.
After his Engineering degree he appeared in the competitive examination and joined the central government in Delhi after 14 years in Govt service He joined Bharat Electronics Bangalore.
In Bharat Electronics in Bangalore, India he rose to the post of general manager before his retirement to Chennai, India, where he lives today.
Sujatha brought freshness to Tamil writing that has been unchanged for the past forty years on diverse topics. His interests include archeology, astrophysics, Biotechnology, neuro sciences, Karnatic music, Tamil literature, sociology and many others.
He is an avid reader and uses his columns as a forum to point out rare good writers, and poets and other artists in general. He is also actively involved in several projects developing software based on Tamil language.