Version 6.3.0 and above are the "re-released" versions that fixed previous security vulnerabilities.
Converter 6.3.0 supports Virtual Hardware up to version 11; higher versions may require manual upgrades after conversion. How to Download from the Broadcom Portal vmware vcenter converter standalone esxi 6.7 download
To download VMware vCenter Converter Standalone for ESXi 6.7, you should use the most current version available on the Broadcom Support Portal . While version 6.2 was the first to officially support ESXi 6.7, it was later removed due to security concerns. Modern versions like maintain backward compatibility and are the recommended choice for current virtualization tasks. Key Compatibility for ESXi 6.7 Version 6