While most people are hoping their Android devices will at some point see a Marshmallow update, there are those still stuck on KitKat. For example, Samsung's Galaxy Tab Pro 8.4 launched last year with Android 4.4 on board, and so far it hasn't seen any big OS updates. So, an owner of this tablet (who's so far been extremely patient, it has to be said) took to Twitter to ask Samsung's arm in the UK about a Lollipop or Marshmallow update for the Galaxy Tab Pro 8.4. @JSmoove_12 We really don't like bringing you news you don't want to hear, but the TabPRO 8.4 will not be getting Lollipop. ^ES Samsung UK (@SamsungUK) November 24, 2015 The answer? Well, in short: no. This tablet will never see an OS version bump. Not to Android 5.0, not to 5.1, not to 6.0. This pretty much means support for this device has ended from Samsung's point of view. It's an interesting development, especially considering that the not much newer Galaxy Tab S 8.4 at least got Lollipop. And that was all the way back in April. But the Tab Pro won't be so lucky. As a final word of advice, keep in mind that this information might only be valid for tablets sold in the UK, since it's Samsung's arm over there disseminating the bad news. Though we wouldn't hope for an OS update for the Tab Pro coming to any other regions...
Source: http://www.gsmarena.com/samsung_says_the_galaxy_tab_pro_wont_ever_get_lollipop_or_marshmallow-news-15186.php