Yes, AUTOCRATIC is a Scrabble word!

Letter values in Scrabble US: A 1, U 1, T 1, O 1, C 3, R 1, A 1, T 1, I 1, C 3.

Is it a valid word?

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

offensively self-assured or given to exercising usually unwarranted power
characteristic of an absolute ruler or absolute rule; having absolute sovereignty

Also: high-and-mighty.