Welcome, Sudakar! Glad to have you join us.
There are likely some Christians here from India, though this is a very cosmopolitan site.
For the others, from Wiki: "
Nadars are predominant in the south Indian districts of Tuticorin, Kaniyakumari, Tirunelveli and Virudhunagar." It is an ethnic sub-group, apparently.
Sudakar, please feel free to clarify or add to the explanation.