It’s being reported that Samsung has begun work for Galaxy S6 Android 7.0 Nougat update, and the 7.0 firmware build no. which is being tested is G920FXXS5DPK7 for Galaxy S6, and G925FXXS5DPK7 for Galaxy S6 Edge.
Samsung is expected to release the final stable release of the Nougat update for Galaxy S7 sets on December end, or January, while it’s bring reported that there is almost no chance the Galaxy S6 Nougat update will arrive in 2016.
You can expect the 7.0 update to drop by in January 2017 for the Galaxy S6 and S6 Edge. Samsung probably won’t release a beta version for S6, and will directly release th stable version because it would have enough feedback already with S7 beta.
With the Nougat update ready for Galaxy S7 in December hopefully, and Galaxy S6 in the line for January release, used of other Samsung sets like Galaxy C5, C7, C9 and 2016 edition Galaxy A5, A7, A9, etc. can hope their own Nougat update too.