Villain's unknown, new to table.

Full Tilt No-Limit Hold'em, $2 BB (7 handed) Full Tilt Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

BB ($103.75)
UTG ($204.65)
MP1 ($84.50)
MP2 ($233.95)
CO ($284.60)
Hero ($281.55)
SB ($200)

Preflop: Hero is Button with A, A. SB posts a blind of $2.
5 folds, Hero raises to $6, SB (poster) calls $4.

Flop: ($12) 6, 5, T (2 players)
SB checks, Hero bets $10, SB raises to $25, Hero calls $15.

Turn: ($62) T (2 players)
SB checks, Hero checks.

River: ($62) 9 (2 players)
SB checks, Hero ???