Oracle Apps 12.2 comes with 12.1.0.2 with startCD 51 and is the suggested for upgrades from 11i or R12.1.3

Its general information that starting with the latest R12.2 installation with startCD 51 comes with 12cR1 -12.1.0.2 which includes the interoperability patches with R12.2.
Future upgrades need to have 11.2.0.4 or higher.

Earlier startCD like 50 used to come with the RDBMS 11.2.0.3 which had to be upgraded to 11.2.0.4 or higher.

Please refer 11.2.0.3 to 11.2.0.4 upgrade steps in my blog.

Thanks