Upgrade vCenter Server from 6.0 to 6.7 U3 (If you have Enhanced Linked Mode then you should to both sites) - If you do not have ELM this is an intermediate step for Site 2.Having said that I suggest you the following:
For the R520 even as it supports 6.5 U3 maximum you have to take into account the next considerations as you are upgrading from 6.0 U2: VMware Knowledge Base Before starting the upgrade you need to have a lot of considerations based on your current versions:
