From the episode 4(season 6)  we can conclude the following :

1. Jane discovers the reason why Brett Partridge was murdered by Red John, as well as the importance of the line "Tyger Tyger".
(Partridge is dead)

2. Jane's list of suspects decreases to five remaining names.
( Kirkland is dead )

I guess Red John is one of them :CBI Ron , Haffner and McAllister