Hello Vikash,
I don't think there is much you can do here.
You found the right note, which clearly says that ERP 6.0 EhP 4 is not supported on Sybase ASE. If you check the Product Availability Matrix (PAM), you will also find that same information.
Product Availability Matrix | SAP Support Portal
Furthermore, if you check the SWPM tool, Sybase ASE is not a possible option on EhP 4, so I reckon you will have to consider performing an EhP upgrade before migrating your DB to ASE.
Best regards
Rui