Yes, TANTRISMS is a Scrabble word!

Letter values in Scrabble US: T 1, A 1, N 1, T 1, R 1, I 1, S 1, M 3, S 1.

Is it a valid word?

TANTRISMS is a valid word in the official Scrabble dictionary (US) and the UK Scrabble Dictionary, but not in Words with Friends (ENABLE).

movement within Buddhism combining elements of Hinduism and paganism
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