Live Tournament Hand - 66 flopping undercards and open ender

[Honest_Rob]

This is a hand from a live tournament I played today. I tried to include all details as accurately as possible. If I left anything out please ask. Some numbers are approximate.

I was just moved to this table. I had to sit the first hand out when I would have been the button. That hand was raised preflop and everyone else folded. No reads on any player. I think I misplayed this hand so please give feedback. I was a little nervous to my surprise because I haven't played live in a long time.

What's your play on the flop?

230 man $100 buy-in NLHE MTT
Blinds: 200/400
Players left: approx: 160
Average Stack: approx: 4,800-5,000

10 handed
UTG(10,000): calls 400
MP(5,000): calls 400
ME Cutoff(7,500): [6s6d] calls 400
Button(2,300): folds
SB(4,000): folds
BB(10,000): checks

FLOP [3s 4c 5d]
BB: checks
UTG: bets 800
MP: folds
ME Cutoff: ?