Downgrading to previous versions
Downgrading FortiClient version 6.0.3 to previous FortiClient versions is not supported.
Network Security 
Network Security
NOC & SOC Management
Enterprise Networking
Business Communications
Zero Trust Access 
Cloud Security 
Hybrid Cloud Security
Cloud Native Protection
Web Application / API Protection
SAAS Security
Security Operations 
SOC Platform
Advanced Threat Protection
Endpoint Security