You can connect the below Registries to a DevTest 10.3.0 Enterprise Dashboard:
DevTest 10.3.0
DevTest 10.2.4
DevTest 10.1.0
DevTest 10.0.0
DevTest 9.5.1
You can connect an earlier version Registry to a later version Enterprise Dashboard, but not vice versa.
For example, a DevTest 10.3.0 Registry cannot connect to a DevTest 10.2.4 Enterprise Dashboard.