Well, i do note somethings: 

1 – There is no antes yet, blinds 50/100 and everybody is deep, so keep that in mind. 

2 – 700 with jacks? that dont make any sence, with aces or kings it makes absolute sense, even queens, u dont want to play big pairs 4-5 handed, with AK i would make a raise 3xbb maximum, hopping to take 1-2 players off (i dont think i would, on that stakes, donks dont give a f***) but also building the pot if i hit big on the flop.
Jacks i would just limp behind and hope to hit a set on the flop and play a big pot, but if the flop comes as good as u can possible hope for jacks, something like 832rain, then i would like to play a big pot against those donks, if they hit that flop with A8s,K8s, J8s, 98s, i do think they would never fold. In higher stakes i would just play it cautiously OP and fold to any big action.

But now, since u screwed up with the jacks, and the action comes to u with a 4200$ pot, u have 3500$ behind, so the pot is just to big for u to call and hope for hit a set or a friendly flop, Its a JAM or FOLD situation, and with that kind of action, i would just fold … i cant see where my jacks is good here, the UTG2 has to have a monster, he limped something pretty big hopping for someone make exactly the play u made, hes range is something like QQ+/AK, i do think u`re ahead of BTN calling range, but u`re definitively behind UTG2. 

Fold is the best line.  

I think you're off ownednutz. If you're going to raise only to 3x after all of these players limped, there's really no reason any of them are going to fold. I really like what I hear recently from pros and instructors and books that you need to stay consistent and not vary by hand strength.

However, I don't think you can be raising here since you aren't that deep. Isn't it taught to go +1 for each limper? If we go that high, you're sort of spewing when someone goes limp/reraise because you really have to fold not having enough chips to properly set mine (unless you assume you're good and able to shove for value against one person, two people, whatever). 

Given what you did, I think you should just get out of the way since we don't really have an idea on what everyone is doing and you don't want to bust this early when you can keep playing with 35blinds. It's likely at least 2 of the 3 people in this hand (after you're out) will be all in on the flop just because of how big this pot will be relative to stacks. I'm assuming utg is calling, which is probably safe to assume. Your hand just doesn't play well against 3 others.

also limping behind is bad imo, raise for value against limpers since so much worse calls. set mining with JJ is bad since noone has a strong enough range to make sure you get paid off.