Sony Xperia M5 and Xperia M4 Aqua Stars Getting Android Marshmallow. Sony is rolling out the update over the air in select regions.
Also Read:Sony Xperia XA is now available to Buy in India
The Update is coming on Sony Xperia M5 with the build number 30.2.A.0.100. Currently the Sony Xperia M5 with model no. E5603 is getting the update, but the other variants including Dual SIM variant will get the will get the update very shortly. On the other hand Sony Xperia M4 Aqua is getting the update with Build number 26.3.A.0.131. The M4 Aqua update has hit select regions. It’s going out to both the Aqua and the Aqua Dual.
Also Read:Sony Xperia X series is up for Pre-Orders in US
The Update includes all the goodies of Android 6.0 Marshmallow i.e Doze, Google Now On Tap, new app permissions, etc. However, if you doesn’t get  the notification yet, then check it manually by going through the settings of the phone.