According to reports, at least three Samsung devices, including the Galaxy A7 (2017), the Galaxy Grand Prime Plus and the Galaxy Tab A 10.1 (2016).have started getting their March Android security patches. While the incoming update for the Galaxy Grand Prime Plus comes with build number G532FXWU1AQB5, the software for the Galaxy A7 (2017) happens to have version number A720FXXU1AQC2. As for the sole tablet on the list, installing the latest update on that device would bump up its build number to T585XXU2AQC1. The incoming update is available as a FOTA (Firmware Over-the-Air) download for all the devices, but neither the exact size of the downloads nor a detailed changelog can be found on Samsung's support pages for any of the devices.
It is important to remember here that the incoming software is only a security update and will not bring any new features to any of the three devices. That being said, the updates are expected to make the devices more secure, so they're still fairly important and should be installed as soon as they're available. Samsung has been rolling out Android security updates to some of its more modest mid-range devices of late, with the Galaxy S5 Neo receiving its own March security patches earlier this week. As is the case with most update rollouts, the incoming update, too, is being rolled out in batches and it may take a little while for you to get the update notification on your smartphone or tablet, should you happen to own any one of the three aforementioned Samsung devices.
Reports suggest the new software has already started rolling out to all the three devices, so it should only be a matter of time before the update hits all the Galaxy Prime Plus, Galaxy A7 (2017) and Galaxy Tab A 10.1 (2016) units around the world. While many owners of these devices are likely to have already received the update notification, users who have not yet received their notifications can check manually for the availability of the update for their device by heading over to the 'Settings' menu, tapping on 'About Phone' or 'About Tablet', and choosing 'Software Updates'. From there, selecting the 'Check for Updates' option should reveal if an update for your device is already available.