The upcoming software upgrade from Google Android Marshmallow will begin its roll out for numerous Nexus devices like Nexus 5, Nexus 6, Nexus 7 (2013) and Nexus 9 starting on Oct. 5.
The upgrade is expected to release along with Google's new flag ship device, the Nexus 5X, according to Android Police. The first roll out batch will be for the current Nexus devices, and will then start trickling down to the other devices as well.
All of the current flagship devices from Samsung, HTC, Sony, etc., are expected to get this upgrade very soon. The Marshmallow code will push to AOSP as well on Oct 5. Android Marshmallow will come in the form of over the air update.
This means that devices will get the update at different times. It is expected to be at least 500 MB in size, as it is a major firm ware update. The notification of the software can be located at the top left corner of the screen. If the users want to check for it manually, they can go to Settings>About Device>Check for Updates
Users can also download the factory image of the update, in case they are using a rooted device and need to do the upgrade, before they get it through OTA.
Android Marshmallow will bring a lot of changes and new improvements in the devices. It is bound to bring the support for the finger print scanner, better Wi-Fi connectivity, Bluetooth 4.2 connectivity, a new API level 23 for enhanced animations, according to BGR. The upgrade is also expected to bring the support for USB Type-C connector, the support for 4G LTE connectivity, and many more.