Patch 6.2.0 was released on Jun 23, 2015 (June 24, 2015 in the EU). This patch was first released on the PTR as build 19890 on Apr 13, 2015. This patch appears to include the opening of Tanaan Jungle and the final assault by adventurers on Gul'dan in Hellfire Citadel.
Build 19906 was released April 16, 2015 on the PTR. Build 19953 was released April 28, 2015 on the PTR.