Re: Firmware upgrade path for FGT-60
The Fortigate 60 is quite old, dating back to 2004-2006 or so. Firmware V3 MR7 P10 build 754 appears to be the last known firmware that I could find on the support site - I could not locate any later firmwares beyond that, despite what that page you linked too have provided says. Considering the age of this fgt, I would suggest getting a newer model.
NSE4/FMG-VM64/FortiAnalyzer-VM/5.4/6.0 (FWF40C/FW92D/FGT200D/FGT101E)/ FAP220B/221C