Direct Translation:
* நாயகன் (naayakan) - This is the most common and direct translation for protagonist, specifically for a male character.
* நாயகி (naayagi) - This is the direct translation for a female protagonist.
Other options:
* முதன்மைப் பாத்திரம் (mudanmai paaththiram) - This means "primary character," and is a more neutral and general term for protagonist.
* கதையின் மையக் கதாபாத்திரம் (kadaiyin maiyak kadhaapathiram) - This means "central character of the story," emphasizing the protagonist's importance in the narrative.
The best option for you will depend on the specific context. If you are referring to a specific male or female character, then "naayakan" or "naayagi" are the best choices. If you need a more general term, then "mudanmai paaththiram" or "kadaiyin maiyak kadhaapathiram" might be more appropriate.