PokerStars No-Limit Hold'em, $1.00 BB (7 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

UTG ($46.80)
MP1 ($39.70)
MP2 ($53.80)
CO ($58)
Button ($49.30)
SB ($113.55)
Hero ($100)

Preflop: Hero is BB with 6, 6.
UTG raises to $3, 1 fold, MP2 calls $3, 3 folds, Hero calls $2.

Flop: ($9.50) 6, 8, K (3 players)
Hero checks, UTG bets $3, MP2 folds, Hero calls $3.

Turn: ($15.50) K (2 players)
Hero ??

Villain is sLAG.
Should Hero bet or go for a check-raise? If betting on the turn, how much?