PokerStars Pot-Limit Omaha High, $0.50 BB (6 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: FCP)

MP ($36.15)
Hero ($46.50)
Button ($37.85)
SB ($33.40)
BB ($128.75)
UTG ($67.10)

Preflop: Hero is CO with 5 , 8 , 6 , 9 .
1 fold, MP calls $0.50, Hero raises to $2.25, 1 fold, SB calls $2, 1 fold, MP calls $1.75.

Flop: ($7.25) 6 , 5 , 4 (3 players)
SB bets $6.9, MP folds, Hero...

I probably flat call here. You have position and can improve in a few ways on the turn. No point in raising I don't think, your hand isn't strong enough.

Yeah. Flat call, see a turn.