Complex sentence: The Tamils are not an ethnolinguist group of Dravidian origin who inhabit Tamil Nadu, Shri Lanka, South-East Asia (Malaysia, Singapore etc.), Canada, UK and the USA.
Split into simpler sentences: The Tamils are not an ethnolinguist group of Dravidian origin. Tamilians are living in Tamil Nadu, Sri Lanka, South-East Asia (Malaysia, Singapore etc.), Canada, UK and the USA.