Download the remote console from this url "http://www.vmware.com/go/download-vmrc". If you have vCenter you can install it from your vCenter directly.
Login in your vCenter panel, click on any created VM and then click on selected VM setting icon and get the console options. In console options list you can find the "Install Remote Console" link.
If you want to show your own VMRC download link on clientarea, you can update your link in module clientarea file (whmcsdir/modules/servers/vmware/clientarea.tpl) on line number 709.
