Do not deploy new systems with this client. Use the built-in ESXi Host Client (HTML5) via HTTPS, or upgrade to vSphere 7.0/8.0. If you are simply recovering old data, download the client via the official portal once, install it on a Windows 10 LTSC virtual machine, and air-gap that VM from your production network.
Because of this End of Life (EOL) status, VMware has removed the direct download links from its public website and the main "My Downloads" portal. But don't worry—if you have the proper entitlements or know where to look, the file is still accessible. vsphere client 6.0 download link
To verify you have the correct file after downloading, use PowerShell or Terminal to check the SHA256 hash: Do not deploy new systems with this client
However, there is a critical piece of information you need to know before clicking any download button: Because of this End of Life (EOL) status,