Samsung has started rolling out Marshmallow update for the original Galaxy J7 (2015) in Russia.
At present the update is being rolled out only to the Galaxy J7 (SM-J700H) varaint. The Marshmallow OTA update is about 1.04GB in size and is now available. The new update would bring in a re-designed, cleaner TouchWiz interface, Doze mode for better battery-life, Now on Tap, App permissions and general performance improvements.
Earlier this month Samsung had also started rolling out Marshmallow update for the Galaxy J5 (2015) in India, and it seems next up on list would be the Galaxy J7.