I haven't posted a hand in ages, so hopefully I'm doing this right. Some of the details of the hand I don't remember exactly. I started the hand with around 2800.

Preflop (30): two limpers, hero makes it 130 in the CO with JJ. Either the BTN, SB or BB calls and both limpers call as well, so four players to the flop.

Flop (530-550, depending on who the "other caller" was): T65. Both limpers check, hero bets 350-400, other caller and the first of the EP limpers fold. The other limper insta-shoves and has hero covered.

Reads: villain limps fairly often but doesn't seem like a poor player overall. Hero probably has a tight image.

My game is pretty rusty and I doubt if I ended up making the right decision. Anyway, his range is probably a few sets (he wouldn't likely limp with TT and he could raise smaller with 66 or 55 sometimes), 65s and of course several draws. Maybe we can add one AA and one AT combo as well. What do you guys think?

His range is heavily weighted to combo draws/pair+draw, imo, as 1)He's looking to maximize FE with his very large raise, whereas his pure value hands would want to protect but would also prefer not to lose their customer and 2) On a board that wet, a lot of his TP-sets would be hesitant to check in case it checked through.

I really think there's no AA in his range to overlimp and then overcall pre. I gave him 2 combos of sets, one of AT, and then 9d8d,8d7d,7d6d,4d3d, and that gives him 55.8% equity. Pot is at least 1230 right now, and it is at most an effective raise of 2320. That means that if you call, total pot will be 5870, and you are paying at most 39.5% of it You'd have to put at least two more pure value combos into his range to get below that level of equity, so I think this is a call.

JJ on this board texture should be betting the big size pretty often. In practice I think this is almost a pure big bet for me though GTO wants you to check it like 30% or something.

At this stack depth I'm never folding to a limp call CR line after I bet big. There are just way more hands that you are winning against than value.

Thanks. I agree with leaving AA out of his range, but 65s should be in there imo. And my flop sizing was a tad too small.

Maybe half the combos of 65s, as he rarely check its, since it checking through would be a disaster for that hand on a board this wet. To be honest, I wouldn't even give him half, but only two are available, so giving him less than one would be a pain in the old school PokerStove that I still use. That still leaves you with 42.3% equity. Even if we give him both, your equity is at 40.8, giving you a mildly profitable call.

I agree that even if you went 400, that's a just a tidge small 4-ways on a board this wet.

I'm leaning towards checking flop 4way. We should be cbetting this flop at a very low frequency so we can't just cbet every overpair. JJ (or QQ) is arguably a better candidate for a bet as it's more vulnerable than AA/KK and we unblock KT AT now.
However, 4 ways our range and actual hand equity isn't all that great though so we don't really need protection. If flop checks around and the turn bricks we suddenly have a reasonable high equity spot and the hand will play out a lot easier on the turn in a small pot. I think it's really good for us to be able to show up with hands as strong as jacks OTT after flop checks around.
As played I'm folding btw, we're flipping or crushed here and the potsize isn't big enough to call.

I actually don't hate a check here in a slightly bigger game. In one this small (is it as small locally as it would be in USA#1, their ranges have a ton of draws I think we need to charge. I don't really hate a check though.

This part, however: What range do you put V on that we don't have 39.5% equity against? You're right that we're usually flipping, but there's at least 1230 in the pot already, and I really think we're crushed pretty rarely here.

With given reads on villain being somewhat solid despite limpcalling i expect villains range to be more pair heavy and have less potential draws in it, the fact he's limpcalling makes me believe he likes to see flops cheeply and play a big pot when he hits big, so his range is just a ton of sets here imo
the flop check-jam is very far out of line to his preflop play, which i find very suspicious (even without reads). Think of it like this: a weak player is unlikely to get very agressive with draws postflop if hes a limpcalling type and a strong player is very inlikely to expect you to fold an overpair on this flop.

Hmm. Good point. I may be projecting a bit. I just don't think very many LLSNL players are capable of CRAI a set here, both due to fear of it checking through and due to fear of losing the customer with the overbet. That said, if he really is decent... There may be more sets in his range than I gave credit for. My population reads would lead me to expect there to be some more history or likely V reads on OP before I'd be comfortable adding more than a couple more combos, though.