The documentation only lists compatibility with 11 and 12:
Supported Data Sources - CA Test Data Manager - 4.6 - CA Technologies Documentation
Some older versions only list 11, and 4.1 and older don't list any DB2 versions, so I can't be 100% sure if any versions ever officially supported DB2 10.x.
DB2 10.1 on z/OS is no longer supported by the vendor: IBM support - Software lifecycle - DB2 for z/OS 10.1.0
10.5 is a LUW only release from what I could find - which isn't as popular, so I'm assuming that you're referring the z/OS version.