Today, Google has started rolling out the Android 7.1.2 Nougat update though the OTA (Over-The-Air) for Nexus 6P Beta testers, while it might still take some time for all Nexus 6P owners.
The update weighs in around 25MB and is readily available for the Nexus 6P beta testers on Android 7.1.2 Beta. Along with the Android 7.1.2 goodies, the update brings a number of bug fixes, general performance/stability improvements, and adds new features including Enhanced notification stability, Fingerprint swipe, General connectivity improvements, and Battery usage alerts.
If you haven't got the notification of this new software update yet, Just go to Software updates menu in Settings, and It will automatically start downloading the latest update. The update will take around 10-15 minutes to get Installed on your device.