Yes, TANTRAS is a Scrabble word!

Letter values in Scrabble US: T 1, A 1, N 1, T 1, R 1, A 1, S 1.

Is it a valid word?

TANTRAS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any of a fairly recent class of Hindu or Buddhist religious literature concerned with ritual acts of body and speech and mind
doctrine of enlightenment as the realization of the oneness of one's self and the visible world; combines elements of Hinduism and paganism including magical and mystical elements like mantras and mudras and erotic rites; especially influential in Tibet