The main reason for it is the fact that the Galaxy J7 and the Galaxy J5 are midrange handsets. Samsung is known for its step-motherly treatment of non-flagship smartphones. This means that even if the Korean tech giant decides to release the new updates to the Galaxy J7, it will still take many months because the marquee phones will be the priority.
As the most trending smartphone of 2015, and also the most popular mid-ranger, XDA Developer Forum members have recently released an Android 6.0 Marshmallow-based CyanogenMod CM13 custom ROM for the Galaxy J7.
However, the firmware is merely an experimental preview version so there might be some bugs in it. Users of Galaxy J7 are advised to exercise caution before going ahead with the installation or risk their devices being bricked.
Users should also be aware that while installing the custom ROM improves the device’s performance and UI experiences, it also voids the company warranty. The company will no longer be liable to provide updates in the future.
Samsung Galaxy J7 users have two options to get the Android 6.0 Marshmallow without using the unsanctioned custom ROM update – wait for the Korean tech giant to officially roll out the update sometime in the future or wait for the launching of the Galaxy J7 (2016) which would surely come out with Android 6.0 Marshmallow as its OS.