Check with Parallels or their support area.
El Capitan Images
I upgraded to 11.
El Capitan Download
Powerful performance lets you run common Windows applications—like Microsoft Edge, Microsoft Office, Quicken®, Visio or Microsoft® Visual Studio — or easily run the most demanding applications, such as modern Windows games on your Mac (Parallels Desktop is the first app in the world that supported DirectX® 11 in virtual machines). This video demonstrates how to install OS X El Capitan in Parallels Desktop.Related Videos:OS X Series: https://www.youtube.com/playlist?list=PLtV4BgZmBpMwLT. Aug 19, 2015 In its latest incarnation that was released earlier today, Parallels Desktop 11 brings full support for Windows 10 features like Cortana and experimental support for Macs running OS X El Capitan.
Parallels Desktop 10 for Mac will run on OS X El Capitan (10.11) as long as you are on the latest update; however it is not optimized or enhanced for El Capitan. You will NOT be able to drag and drop files from Windows to Mac or use Windows Applications in full screen*. To enjoy an El Capitan optimized version of Parallels Desktop, please upgrade to Parallels Desktop 11 for Mac.
To ensure you are on the latest update of Parallels Desktop 10, please follow these instructions: KB111603
Parallels Desktop For Mac El Capitan
Apr 3, 2016 1:46 PM