Finally Microsoft released free beta preview of Office 2016 for Mac , its been over five years since Microsoft released its Mac Version Office updates, New features were Cloud and OneDrive,
New Mac user interface is designed from the ground up to take advantage of the latest Mac features, including retina display and full-screen view support , also redesigned Ribbon and your favourite cross-platform features and keyboard shortcuts, you will be up and running with new office for Mac in no time
The preview will expire around 60 days after its release !
The new Office for Mac is officially support on machines running Yosemite ,Microsoft update office regularly , and you will receive the update via a notification from Office for Mac Auto-Update tool
also you can install New Office 2016 Preview alongside with old Office 2011 :), you can download office preview from below given link