Google posted the Android 7.1.1 factory image and OTA files for the Nexus 6 yesterday. That’s news because it was the last remaining device supposed to see 7.1.1 without those files. Google must have fixed whatever final bugs were holding the update back.
You can grab each image or OTA file at the links below. For instructions on how to flash a factory image, here you go. For instructions on how to flash an OTA .zip file, here you go.
Links: Factory Images | OTA Files