UTG: 48.19 BB
MP: 49.85 BB
Hero (CO): 64.92 BB
BTN: 47.23 BB
SB: 81.47 BB
BB: 104.87 BB

6 players post ante of 0.11 BB, SB posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 2.19 BB) Hero has A 3

fold, fold, Hero raises to 2.49 BB, fold, fold, BB calls 1.49 BB

Flop: (6.17 BB, 2 players) 6 4 A
BB checks, Hero checks
I know it can be a cbet-range spot.
My thinking was : I don't have 3 streets of value and there are not many scary turns.
So I prefer taking the value later / letting V bluff / letting V hit a second pair

Turn: (6.17 BB, 2 players) J
BB bets 4.19 BB, Hero calls 4.19 BB
So far the plan is working good

River: (14.56 BB, 2 players) 5
BB bets 9.9 BB, Hero calls 9.9 BB
In game I wanted to stick to my plan. And also I thought I underrepped my hand a little so the call was probably good.
Reviewing the hand though, I believe V's line is strong, so I only have a bluff catcher, and a pretty bad one blocking the clubs.
Also those strong lines are value heavy at low stakes I think, so I don't like my call

Thoughts ?

Preflop
Standard open.

Flop
I like checking back weak AX here, especially when its a rainbow board.

Turn
As you say plan working out so far.

River
On the flop your plan was to make it a 2 street hand on a clean runout. Bet turn, bet river, if he check again. Or call, call, if he takes over the betting lead. And I dont see any reason to change that plan. Yes he is betting more than half pot, which is somewhat large for a tournament, but stacks are deep, and its only for a small fraction of his stack. So I dont read this line from him as being all that strong. I certainly think, this sizing could be used as a bluff as well as for value. There are not any busted draws on this board, but because you checked back the flop, he did not need to have a draw to get to the turn. So I dont think, that really matter.

I also dont think, it matter to have clubs. Hands with Ac have top pair, so they are not bluffing, which mean you only really block bluffs like T3 of clubs, 93 of clubs and so on. And you also block all AX hands, which is a big part of his value range. Any AX is a better hand to call down with than for instance KK or QQ. So for me I like the line, you took in this hand, and I am definitely not folding to a river bet of this size. If he polarizes more like betting full pot or overbetting, then we can start to talk about it. But for this sizing its pretty much a snap for me, and if he has it this time, then good for him.