In case of multiple vCenters in the environment

To keep thing simple you should import the VirtuCache Manager OVA to the vCenter that manages the ESXi hosts where VirtuCache will be installed.
But if you have multiple vCenters, then you can import the VirtuCache Manager OVA in any vCenter so long as there is network connectivity from the VirtuCache Manager VM to the ESXi hosts where VirtuCache driver is installed and to the vCenter managing those ESXi hosts.
VirtuCache Manager appliance should also be able to resolve the ESX/vCenter names/FQDNs (using DNS or WINS/NIS, etc)