If you wish to use the EPDM API to access file data, the answer is no: VB6 is not supported.
If you wish to perform normal file access operations (open, write, close, copy, etc.) you should be able to do so normally using VB6, provided that the client machine is logged in to the vault.
If you wish to access SQL Server data for the EPDM vault, you should be able to do that, too, in the normal way. Just don't change any data or tables in the EPDM database or you'll violate your subscription agreement.
Very helpful. Thanks, Brian!