Hi,
You can install any version of vCD to a vSphere cluster but also to a single host. It does not matter if DRS is enabled. For the appliance version it imports as a OVA. For the binary version, you can install it on compatible RHEL and CentOS VM.
The resource cluster (where the actual customers VM's run) must indeed have DRS enabled. Since vCD depends on Resource Pools. After you have installed vCD you can only add a vCenter server that has NSX enabled. This vCenter server manages the resource cluster.
