Google has apparently started rolling out the Android 6.0.1 Marshmallow update. According to a tweet from the usually reliable leakster @LlabTooFeR, the update is currently only rolling out to Android One devices.
As I said 2 days ago. Android 6.0.1 become available for Android One program... pic.twitter.com/ap8NL4lImE— LlabTooFeR (@LlabTooFeR) November 20, 2015
As for the update, reports say that it's a minor one bringing some bug fixes and stability improvements, although a quick look at the image shared by @LlabTooFeR (see above) suggests that it also includes Google's December security patch.
Reportedly, the Cherry Mobile G1 smartphone in the Philippines is among the first Android One devices to receive the Android 6.0.1 update.