LG recently announced that they would be updating their current flagship the LG G4 to Android 6.0 Marshmallow quickly. There has been no official word on when the roll out would occur. LG must be getting close to an official release. Autoprime posted a build labeled "20A" which could be close to a release build. You can flash this in TWRP. The build is for the South East Asia version of the device H815. While this may not work on your particular model it is exciting to see that we are getting close to an official release. It is also very refreshing to see OEMs make updates a priority!
via XDA