PokerStars - €0.02 NL (6 max) - Holdem - 5 players
Hand converted by PokerTracker 4

CO: 139 BB (VPIP: 12.90, PFR: 12.90, 3Bet Preflop: 0.00, Hands: 64)
BTN: 301 BB (VPIP: 31.88, PFR: 14.29, 3Bet Preflop: 3.36, Hands: 426)
Hero (SB): 135.5 BB
BB: 145.5 BB (VPIP: 20.48, PFR: 19.28, 3Bet Preflop: 0.00, Hands: 83)
UTG: 418 BB (VPIP: 72.60, PFR: 4.11, 3Bet Preflop: 0.00, Hands: 75)

Hero posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has A 8

UTG calls 1 BB, fold, fold, Hero raises to 5 BB, fold, UTG calls 4 BB

Flop: (11 BB, 2 players) 8 6 A
Hero bets 7 BB, UTG calls 7 BB

Turn: (25 BB, 2 players) J
Hero bets 18 BB, UTG calls 18 BB

River: (61 BB, 2 players) T
Hero ???

Villain is 72/4 so he can anything here, draws being the most likely on this board. The T OTR is an awful card because it completed not only the obvious FD but also some SD. So, what should we do here? Just check/fold and check/call a small bet? or can we bet/fold?

You can check, in my experience these kind of villains will let you know if they made a flush or a straight by betting out big, so you can call a small bet and fold otherwise.

The alternative is to thin value bet like 20bb. This guy likely open limps A2 through to AT and is very sticky with his TP. So there are several combos there that will pay you off plus any two pair, Jx etc. If he raises, just fold.

EDIT

Plugged some ranges into Equilab, I think we are in good shape against his calling range. We should bet IMO, probably more like 30bb.

Bet/fold imo as he'll never fold any Ax