His zeal to serve the downtrodden made him appear in the Justice K. S. Ramamurthy Commission, which was set up on his insistence, investigating the rape of 17 dalit women in Sankanankulam village, India in 1980-81 on behalf of the victims, fighting for their cause.

After noticing his dedication and commitment towards the society, the then Chief Minister of Tamil Nadu Thiru M. G. Ramachandran appointed him to assist Shri Ashoke Kumar Sen in the commission investigating the IMFL Licensing system in 1983-84.

He served as Trainee District Judge, Coimbatore from 1987–1988; subsequently he was posted in the following stations:[3] During his stint at Dindugal, alleged henchmen of the then incumbent government occupied the Kodaikanal International School in the middle of the night thereby evicting all the resident students from their boarding quarters.

[5] On 21 July 2014, Press Council of India Chairman and former Supreme Court judge Justice Markandey Katju made allegations of corruption in the judiciary.

Ashok Kumar was elevated as Additional Judge of Madras High Court in April 2003, a period when the DMK was part of the NDA.

He again proved his mettle while dealing with a case in which 78-year-old former Chief Minister (as he then was) Mr. M. Karunanidhi was arrested at midnight by the police at later produced before Ashok Kumar around 4:30 a.m. and was remanded to judicial custody.

[16] The Hindu, the national daily, observed that Mr. Ashok Kumar is a firm believer that judicial pronouncements have to be severe, when it comes to protecting rights in a civil society.

"The orders of this Judge, as the average citizen has found, combine sharp, but impersonal law points and a subtle warning to keep executive excesses well under check".