According to Tablety.pl, LG is finishing up its final round of testing for the LG G3′s Android 6.0 build and is planning to release the new software update starting in Poland between December 16 and 18. LG customers in Poland have been the first to receive major Android updates in the past, but there’s no reason why LG shouldn’t also release the update to other unlocked versions of the G3 around the same time.
It will be a different story for the US market and carrier-branded versions of the LG G3 in Europe and Asia. LG has done an incredible job of updating its unlocked phones, but they have had a few issues getting service providers to test and release updates for its phones in a timely manner. Based on LG’s track record, we don’t expect to see Android Marshmallow released for carrier-branded versions of the LG G3 until late January or even early February of 2016 — after LG gets the update rolling for the LG G4.

Source :
Androidandme