While your specific version string "415 1" appears to be a typo or a repackaged version often found on third-party sites, the official releases follow a standard numbering system. The current stable 64-bit release is Wifislax64 4.0
While "4.15" is not a standard release number, the development branched into a dedicated 64-bit architecture after version 4.12. Wifislax64 4.0 (Latest Final): wifislax 415 1 iso download 64 bit extra quality