G. K. Mani, was born in Govindapadi Village, Kolathur, Salem District, and belongs to the Vanniyar community. His involvement in social work began as teacher in a Govt. Aided School in his village. He subsequently joined the Social Service Society (SSS), which was later merged with the Vanniyar Sangam, a social organization founded by Dr. S. Ramadoss that aimed to provide the Vanniyar community with social and economic mobility.
In 1986, G. K. Mani, was first one to be elected as Union Chairman for Kolathur under the Vanniyar Sangam Banner. He is the first political representative from Vanniyar Sangam even before the PMK party was formed, and was a member of the Tamil Nadu Legislative Assembly from Pennagaram constituency, having been elected most recently in the 2021 Tamil Nadu Assembly Elections. He had represented Pennagaram three times; he was first elected in 1996,[4] reelected in 2001, and again 2021. He was also elected once from Mettur constituency in 2006.
When PMK borke in 2025 he alliened himself with Ramadoss faction, Ayya Pattali Makkal Katchi.