It will come with Android 6.0.1 Marshmallow OS with touchwiz UI on top. (galaxytabreview.com)
Android 4.1.2 XWLSU Jelly Bean features Project Butter, Nature UX with TouchWiz interface, expandable notifications, more and new toggles, brand new lock screen functions, Google Now and multiple others. (android.gs)
The device will ship with some of the coolest features including with Smart Pause and Resume, Smart Scroll, Dual Camera feature (to let you capture photos and videos with the front and rear cameras simultaneously), S Health, S Travel, S Translator (supports 9 languages at launch), Group Play, S Voice Drive, Samsung Adaptive display, and it will boot Android 4.2 Jelly Bean OS with new version of TouchWiz UI on top of it. (gadgetian.com)