According to Artem Russakovskii (Android Police), the Nexus 7 (2013) is definitely going to receive the latest Marshmallow taste. But the Nexus 4, Nexus 10 and Nexus 7 (2012) won’t, given their old age / hardware.
Android 6.0 Marshmallow is expected to make an official introduction into the wild on September 29th, along with long anticipated two Nexus smartphones – the Nexus 5X and the Nexus 6P. Just days ago, it was reported that Android 6.0 Marshmallow would make it out on the Nexus 5 and Nexus 6 on October 5, at least in Canada because the report was supplied by the Canadian carrier TELUS.
But we now can not say when the latest Android update will hit the Nexus 9 or Nexus 7 (2013). We’ll have to wait and see, but good chances will be the end of October.