Yes, OTTOMANS is a Scrabble word!

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

Is it a valid word?

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

a Turk (especially a Turk who is a member of the tribe of Osman I)
the Turkish dynasty that ruled the Ottoman Empire from the 13th century to its dissolution after World War I
thick cushion used as a seat
a low seat or a stool to rest the feet of a seated person

Also: ottoman turk, ottoman dynasty.

Not playable in Scrabble US: OSMANLI.