You can see the list of confirmed titles (games, tools, etc) that are already released here: MixCast-Ready Titles. If the title isn't listed, check with the developer about MixCast support. If you are a VR developer yourself looking to add support for MixCast broadcasting, find out more on our SDK Details page.
However, we will save you some additional clicks and make you aware of a few high profile titles that doesn't support MixCast (yet!) and how to get in touch with the developers to change that: