Full Tilt No-Limit Hold'em, $0.50 BB (6 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

MP ($110.40)
Hero (CO) ($50.05)
Button ($65)
SB ($79.25)
BB ($27.95)
UTG ($50.25)

Preflop: Hero is CO with ,
UTG bets $1.75, 1 fold, Hero raises to $6.50, 3 folds, UTG calls $4.75

Flop: ($13.75) , , (2 players)
UTG checks, Hero checks

Turn: ($13.75) , (2 players)
UTG checks, Hero bets $5.50, UTG calls $5.50

River: ($24.75) , (2 players)
UTG checks, Hero checks

Total pot: $24.75 | Rake: $1.20

Obviously, I don't have the nuts here but I think I should have bet for value. It has to be a bet/fold because as he played it, he could have KJs,JJ,TT,99, KTs, KK even though these are highly improbably statistically, all are in his range for a 3bet call OOP UTG. Should I have bet/fold the river and how much? Thanks