Okay, somethings I want to point out after watching 6.06 again. Not very valuable stuff but mainly observations that someone could pick up for a proper theory.
a) The Pistol in Jane's belt is the proof that he set up his own house to explode. He will go undercover as a dead man for a while so he will have to leave the shotgun as evidence, therefore he's already prepared with a gun in the pocket since the very start of the longcon.
b) The Mentalist. Jane is measuring every single movement of the suspects, this is no reveal. He made the reunion in his old house, and take for sure he will be measuring who gives a hint of being there before, because clearly Red John has.
c) The 3 dotted suspects. I believe the boss in this club is McAllister. Certainly there's something with him. He is very perceptive Jane's call is about RJ, and when he reveals the Tattoo he kinda smiles at Jane, his body isn't frontal to Jane as the other suspects are, and besides he acts as if he commanded the group. Watch the scene again, he's the first one to stand up when he's told to, and he constantly smiles, or looks at the other tygers, as if he was controling them.
Specially in key moments of the shot like when Reede stands up, or when the three of them are against the wall and they turn to face Patrick, he looks at the other two like checking they proceed as planned. There's even a brief shot of Patrick pointing McAllister in which we can only see his mouth, and he's clearly smiling.
He's the only one of the three that makes Patrick uncomfortable, check their eye contact.
However, Haffner is my number one suspect based on all the other evidence. And I rule out Stiles, which is clearly the other survivor. Why? Easy. If he was RJ, Haffner would know. If Haffner knew, he wouldn't have given up his location to Lisbon, no matter how much Ray fances Teresa.
Ray also acts weird, he has the same reaction both with Teresa and with Patrick when he's told basically the same thing (that he's a suspect). Why would he react that way with Jane if Lisbon almost told him that? I think it's an acting.
And yes, finally I agree with those who say that Jane would stand exactly opposed to the main suspect, which would be Ray.
Having them stand and separating the suspects in the two main groups we all theorists know was key. It might mean many things, up to the writers intelligence. I believe that giving his back to the two visualizers and considering how close they were to the guns was a strange way in which Jane could have tried to tempt RJ to shoot him, had he been one of those.
On the other hand, and by 6.08 if RJ turns out to be Ray, we will still be doubting why he didn't kill patrick in that moment.
So I believe it's one of those two. Haffner or McAllister.
I want Red John to be one of those two. McAllister looks in that shot give me creeps, he's the hell of an actor and could make a really good psycho.
Ray has this crazy weirdo eyes that also would make a good RJ,let alone he fits in almost everything, and that he is smart too, when he wants to show it, like with Teresa at the cafe, he also figures out is about RJ (like did the sheriff).
I wanna say also that those two (ok, let's put stiles in, and we have the final 3 suspects the series is giving us) have the most consolidated relationships with PJ. McAllister plays as a friend this last episodes, Haffner clearly is opposed to Jane, and Stiles likes him, but clearly isn't dependent on him (as RJ definetely is).
So, this is my point of view based on something "close" to what is generally called "logical thinking". However I believe the writers might fuck everything up. I mean they already started it with the list, and then based on that article in the magazine (spoiler jpeg) they established that the Tyger Tyger organisation is Red John's. That's plain stupid, why would RJ acknowledge his nemesis of the existance of a secret web? It doesn't make sense.
That's why I said that I want RJ to be either Haffner or McAllister, but I'm afraid we're gonna have other cake