If you are not familiar with wsadmin.sh (Linux) / wsadmin.bat (Windows), check out my article Getting Started with wsadmin.

Here is an example of how to list Java Virtual Machines using wsadmin.

~]$ /opt/WebSphere/AppServer/profiles/your_profile/bin/wsadmin.sh -lang jython -c "print AdminConfig.list('JavaVirtualMachine')"
WASX7209I: Connected to process "dmgr" on node Node01 using SOAP connector;  The type of process is: DeploymentManager
(cells/Cell01/nodes/Node01/servers/dmgr|server.xml#JavaVirtualMachine_1)
(cells/Cell01/nodes/Node01/servers/AppSrv01|server.xml#JavaVirtualMachine_1699553133969)
(cells/Cell01/nodes/Node01/servers/nodeagent|server.xml#JavaVirtualMachine_1699546101364)
(cells/Cell01/nodes/Node01/servers/WebServer1|server.xml#JavaVirtualMachine_1699558926383)