Samsung is rolling out March Android Security patch on bunch of its Android devices. The devices are Galaxy Note 4, J1 Ace and Tab A (2016). The update is coming with the build N910FXXS1DQC3 on Galaxy Note 4, software build J110HXXU0AQC1 on Galaxy J1 Ace and P585JXU2AQC2 for Galaxy Tab A 2016.
Along with the security patch the update also packed with some fixes to bugs which gets rid of several vulnerabilities thereby making it difficult for hackers to get hold of the sensitive data on your smartphone. We recommends you that before start installing update charge your phones battery.
The update is rolling out as OTA so it might take some time to reach you. If still the update notification is not there on your phone just check it manually by going through the settings of your phone>>About Phone>>> Software updates.