It sounds like you may be looking for the offline (standalone) installer for FortiClient VPN version 6.4, rather than the online web installer that downloads components during setup.
“That’s not the real name,” Mariam said. forticlientvpnonlineinstaller-6.4 offline installer
(a small executable that downloads the full software during installation), many IT administrators prefer an offline installer It sounds like you may be looking for
The Evolution of Remote Access: A Deep Dive into FortiClient VPN Online and Offline Installers Use the MSI/EXE offline package with silent switches
The primary driver for the demand of an offline-capable installer (or the full standalone package) is enterprise efficiency. In a corporate environment, bandwidth is currency. System administrators deploying FortiClient to hundreds or thousands of endpoints cannot afford to have each individual workstation contact an external server to download the same files. This process would saturate network bandwidth and introduce latency. Instead, the administrator requires the offline package to host on a local internal server or deployment tool (such as SCCM or Group Policy). By possessing the full 6.4 installation file locally, the IT department ensures that the deployment is rapid, consistent, and does not rely on the fickle nature of the external internet connection.