Android 6.0 Marshmallow was released in early October. So manufacturers have started working on providing the official Marshmallow support for various devices. It will take time for them to roll out the updates. For Samsung devices, we have leaked document which gives the ETA of when Samsung devices will get the Marshmallow update.
The first Samsung device to get the official Marshmallow update will be Samsung Galaxy Note 5. And it will be the only device of Samsung to get Marshmallow this year.
Other flagship devices like Galaxy S6 Edge+, Galaxy S6 Edge, Galaxy S6, Note 4, Note Edge, etc will get the Android Marshmallow update in January.
Some devices in the Galaxy A and Galaxy J series will also get Marshmallow updates which is a welcome news. They will receive the update starting from March.
Samsung’s tablets will also receive the Marshmallow update starting from April. For Galaxy S4 and Galaxy Note 3, there is still no approval for Marshmallow update.