COBOL V6 support was added to CA MAT 11 in INCREMENT 2:
Title: MAT V11 INCREMENT 2
* Initial Dashboard Summary Reporting
Install Enhancements to base MAT and GUI
Support for VSAM RLS Phase 1
Support for Enterprise COBOL V6.1
Normal PTF published
I don't see any other PTF created that involves COBOL V6, so as long as you have the incremental fixes on you should be OK.