Yes, TICKETS is a Scrabble word!

Letter values in Scrabble US: T 1, I 1, C 3, K 5, E 1, T 1, S 1.

Is it a valid word?

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

a commercial document showing that the holder is entitled to something (as to ride on public transportation or to enter a public entertainment)
a label written or printed on paper, cardboard, or plastic that is attached to something to indicate its owner, nature, price, etc.
a summons issued to an offender (especially to someone who violates a traffic regulation)
a list of candidates nominated by a political party to run for election to public offices
the appropriate or desirable thing

Also: just the ticket.