Hi
you can try going to marketplace -> Release and Upgrade info -> release notes. On the left hand panel expand sap solutions -> R/3 -> 4.6 . Release Notes R/3 4.6C (for the first step)
Then repeat the same for SAP R/3 Enterprise 47x200 and SAP ERP 6.0
Obviously there are more releases in the middle but this could be a good brief summary
Regards
a