You can view this property on the Deployed Process Version Detail.
The options for setting a process version offline or online are:
To inactivate this version at a specified date and time, type in the values in the Offline Date fields.
To inactivate this version immediately, select
Set to Offline
. No new process instances can be instantiated from this version. The status is Offline Pending until all running processes complete.
If you had previously set this version offline, you may be able to restore it. To restore this version to the online or online pending (future) version, select the available option,