sap upgrade

Hi ALL,

We are planning to upgrade our SAP system from 4.6C to ECC6.0 .Please let us know what are impact occur in RFC Connection to other systems due to the upgrade .The parameters like Support pack, plug innu2019s ,add onu2019s etc of the systems connected with other systems like BI,SCM,HR,,..

Does ECC6 will support all the special output devices in 4.6C..or do we need to investigate that....?

Regards,

Balaj.R