It is bad to play against an unknow reg, since you can´t assume anything from his flat range at all. 

Probably he will 3bet most of his premiuns, flat with suited stuff , connected and some PPs. 

That being said I would bet a little less OTF , to induce some raises, induce some floats and two make a 3 street hand with a good ammount of FE OTR. With that betsize OTF you kind of need to go a little smaller OTT to make a bet OTR with a good FE. Plus, when we have air we want to go smaller OTF and that accomplish that as well. Just bet bet bet and count with some FE if the draws didn´t hit :) 

I like b/f OTT vs unknown, if he raises you can happily muck your hand or call with ~24% equity. If you barrel turn you can get hands like 55,88-JJ (AK?) that floated to fold and potentially get called instead of raised by 44, 66, 77, QQ, KK, AA which gives you a chance to river a diamond/5/A.

I only say villian calling with monsters is, because he is IP and if he just calls turn he can still jam river in the event you check. But he may just Raise turn, just saying there's a potential for the above to happen which I feel is the most ideal line for our hand and this board.

@Edichka1

I didn´t mentioned that we should bet smaller with draws and air and bet big for value, whereas it seems I mean it, sorry maybe it was my fault since english isn´t my first language. 

I just think overall bet smaller accomplish better our plan to bet 3 streets, like u said, I do think that a Q OTT will hit our range a lot of times and sometimes we are betting here for value (it´s not the time with that hand) and sometimes maybe just trying to rep the Q

I think b/c and x/shove are close together. I think b/f would be really bad.

I´d start with 3-betting bigger pre oop though, make it $6. If I flop that strong I try to make it a two-street-hand, you could even overbet the flop and shove the turn.

I think i like bigger flop bet and shove turn.. If you bet closer to PS on the flop you have just about a PS bet left on the river.. He has a lot more 88-JJ hands than he does sets, and he would likely raise the flop at least some of the time with a set.. The Q should not really help him at all..

Given how you played it, i am still betting the turn because i think he will be folding a lot of 88-JJ as mentioned above.. Also, i dont think you can really b/f the turn here. Even if you bet 1/2 pot you would have ~$26 left, you are getting the right price with just about any hand he may have.

is a bad option  c/r flop and OTT shove?

Not at all, imho ... somehow I forgot to mention that.

I d bet bet shove or play the tricky c/r the flop idea depending on my overall gameplan vs villain. Facing a shove on the turn would be unfortunate but decently unlikely. Whether or not to call is going to be close I m sure.

Thank you all for your answers, it really helps me.

Board: 6h 4d 7d Qs

 Hand 0: 77.273%           { 66 }

Hand 1: 22.727%         { Ad8d }

Lets just say worst case scenario we bet turn $15 and he shoves and its $24 more to win a final pot of 100, so we need 24% to call and we have 22.8% against a set. So the EV of calling when he has a set is - 1.2%*100bb= -1.2BB in EV or -.60c. Which isnt that bad considering worst case scenario! So things betting the turn has going for it... 1) He wont always shove turn! 2) Leaves our options open otr 3) keeps it more simple....we do not relinquish control and have to guess about his range (i.e. thinking about what hands he will check back vs bet ott) 4) good for our overall range considerations  

I do not like check/shipping because he is rarely betting something that he is ever folding over taking the free turn so our fold equity is very limited. I do not like bet/folding because that just feels so theoretically flawed and the line I most want to avoid with this hand.  

Agree with the above.

Bet sizing is too small for sure. 5.25 is bets (3.5x OOP against 3x opens).

Just don't fold.  You generally want to get the last bet in here in order to luck up some fold equity.  So it's natural to play your hand as either a flop x/r followed by turn jam, or as a flop x/c followed by turn x/r, or as a flop cbet followed by turn x/r, or as a near potsized cbet followed by a near potsized turn jam.