ZEE5 has arguably the most aggressive Tamil web series lineup.
If you are thinking of a Tamil series about a cop or a vigilante trying to make things right (often misremembered as "Better"), you might be thinking of "Iraivan" or similar crime thrillers popular on Tamilyogi. tamil web series tamilyogi part 5 better
The Long Story:
Sony has entered the game with high-budget productions. ZEE5 has arguably the most aggressive Tamil web