I think it will be quite difficult for Atletico Madrid to take 3rd place from Girona because there are only 6 matches left, while Atletico Madrid has a performance that is no better than Girona. Likewise with Barcelona, I think their chances in the title race are gone because their points gap with Real Madrid is getting wider. Barcelona played quite well when playing at Real Madrid's home ground, it's just that when it comes to mentality and composure, Real Madrid is still better than Barcelona. I think what can change is 2nd place and third place because for now Barcelona and Girona are only 2 points apart.
Yes, with just 6 matches in hand, a gaining a point difference of 8 points with an equally performing team require an spectacular performance and a rare luck. I don't see Atletico Madrid Catching up with Girona. It's more likely that Atletico Madrid try not to get replaced by Athletic Club which is right behind. Atletico needs this position to play next champions league.
I don't see Real Madrid being challenged as well while the two Catalonian team might fight for the 2nd spot. Barcelona has uped it's game recently while Girona has a decreased gameplay. I expect the standing till top 5 to remain the same even at the end of the league.