Webex will install to different locations based on the service type and site version used. You may host and present from a Mac as long as your operating system and browser are supported by the Webex site. To determine if your Mac OS is compatible with your Webex site, see:
The Webex Desktop App is compatible with supported versions of Mac OS. Is The Webex Desktop App Supported for Mac?
See table below regarding Mac compatibility: Are there any common known issues for Mac OS? Common questions regarding Mac and Webex compatibility.