Yes, OCCUPIER is a Scrabble word!

Letter values in Scrabble US: O 1, C 3, C 3, U 1, P 3, I 1, E 1, R 1.

Is it a valid word?

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

someone who lives at a particular place for a prolonged period or who was born there
a member of a military force who is residing in a conquered foreign country