We’re only 2 days in April, and already the security patches for this month have started to roll out. The Galaxy J3 (2016) is already snatching its own update, coming with the model number J320FXXU0AQC3.
The update brings some regular bug fixes, as well as some device optimization as well. It might take some time for your device to receive the update as well. Of course, you can always check for the update manually in the Settings menu.