Hello,
You may want to read this page about Capella and SysML: https://www.eclipse.org/capella/arcadia_capella_sysml_tool.html
You can reproduce somehow the activity diagrams in Capella. But the SysML language is not implemented by Capella. Hence, constructions such as interruptible activity regions are not implemented neither.
However, the intended behaviour can be represented using other means. For instance, using Modes States Machines, specifying the functions that are enabled on each mode and the exchanges that trigger a transition to another mode.
Hope this helps.