Your vCenter Server 6.0 deployment type does not change during the upgrade to version 6.5.
The vCenter Server example upgrade paths demonstrate vCenter Server 6.0 upgrade outcomes.
The installer upgrades vCenter Server 6.0.x with an embedded Platform Services Controller instance to vCenter Server 6.5 with an embedded Platform Services Controller instance. The software upgrades vCenter Server and Platform Services Controller instance in the correct order to the same version.
The installer upgrades an external vCenter Server 6.0.x instance to an external vCenter Server 6.5 instance and an external Platform Services Controller 6.0.x instance to an external Platform Services Controller 6.5 instance.
If you have multiple systems configured for high availability, vCenter Server enables you to incorporate your common services into an external Platform Services Controller configuration as part of your upgrade process.
If you have a multi-site setup configured with replication, you can use vCenter Server to incorporate your common services into an external Platform Services Controller configuration as part of your upgrade process.
For more information on mixed version transitional environments, see Upgrade or Migration Order and Mixed-Version Transitional Behavior for Multiple vCenter Server Instance Deployments.