If you deny existence of Ram, you must also deny the existence of Lord Muruga, the most popular diety in TN. Muruga, better known as Karthikeya in North India is the son of Lord Shiva, who is one of the trinities of Hinduism. Similarly, Lord Ayyappa, whom TN people worship is the son of HARI AND HARA (Vishnu and Shiva. If you accept the existence of Vishnu, you cannot deny any of his AVATARS, of which RAM is one of the formost.