Read here: List of Android devices which are set to receive the Marshmallow update
Android Marshmallow has been officially out for quite a while and users of various Nexus devices except those of Nexus 4, Nexus 10 and the original Nexus 7 (2012) have been enjoying the various perks and benefits that it comes with. Even though changes to various Google services have been rolled out via application updates
Source: Neurogadget