If you have an ESXi 6.0 host running, you can download the client directly by navigating to the host's IP address in a web browser. The "Getting Started" page usually contains a Download vSphere Client link [1, 16, 22].
https://download3.vmware.com/software/vsphere/60/VMware-viclient-all-6.0.0-XXXXXXX.exe vsphere client 6.0 download link