On the river he reps only 67s and maybe 9Ts, maybe QcJc but thats just 1 combo, however when he just overcalls on the flop he pretty much always has a draw or Tx, I dont think he turns like QTs into a bluff.So you are left playing pretty much against 3 combos of 67s(he should raise 6c7c) . Now when I think more about it I doubt he would do that with two pairs cause u would bluffcatch with sets also. Ok so lets put QcJc, and 67s, so 4 combos. What about bluffs, AcXc? I think you would call with all the sets here, so calling with QQ would be too much? but its pretty tough since he doesnt have that many value hands.. if i had a lot of time to think about i would probably find fold, but if i had like 5 seconds i would snap call :D dont think that calling can be that bad though so wouldnt worry too much about this

and its also a question if he would bluff the river since after two strong bets into 3 people you look like youre going to check call