Hi Girish,
Remote plugins are serving the UI resources directly from the vendor backend appliance.
If it runs Java you can use the vSphere Web Services SDK 7.0.2 (vim25) which is available here: https://code.vmware.com/web/sdk/7.0/vsphere-management
Note these are backend APIs, hence you don't see this in the Remote plugins guide which is covering vSphere Client SDK.
That said, the vSphere Client SDK contains a remote-plugin-sample which demonstrates the usage of vim25 Java APIs.
Please check that for code references.
Cheers,
Vladi
