Hi @August Tam ,
in short: No, that's not possible.
Long Version, because old men love to speak about old times :-) :
Opalis 4 was Opalis Robot. Opalis 5.x and 6.x were Opalis Integration Server.
It's not possible to upgrade from Opalis Robot to Opalis Integration Server directly. There was a Migration Tool provided by Opalis to migrate an export from Opalis Robot to Opalis Integration Server.
The Migration Assistant was available until version 6.0 of Opalis, available in the Setup Package (\Opalis Integration Server 6.0_6.0.0.4512.zip\MigrationAssistant).
I don't recommend to use this!, because the objects that are migrated to are so called "Legacy Objects", only available until Opalis 6.3., not supported in Orchestrator.
Regards,
Stefan