NL400 ATo

I think that are just two options
1/ value bet
2/ check/fold

I rly cant see any hands except few missed FD which he could bluff if you check. On this specific river all hands like QT/KQ hit SD. And also you have notes that he gives up OTR, which convince me that check/calling is just bad.

I have made some simulations and you need him to call at least all KQ/KJ to justify valuebet and it seems to me too thin.

I would probably check/fold.

Another options is to turn hand into bluff, but I think you would massively overbluff this spot if you turn AT into bluff.

Hi

I agree with banker here. This is a check/fold and villain shouldn't have too many busted draws here. Don't forget your raise size is pretty large so unless he is really loose and wants to play with the fish badly, I think that his range is gonna be pretty broadway heavy and he shouldn't have all that many flush draw combos.