Geo Blocking/Fencing and IP Monitoring are available in the NSX infrastructure version 9.0 but, unavailable to enable.
NSX 9.0
vDefend 9.0
This due to a VMware vDefend Firewall License not being applied to NSX.
A VCF license and vDefend license will have to be applied in NSX to utilize vDefend components. The VMware vDefend License document states, "When you add the VMware vDefend Firewall license on the NSX Manager UI, the vDefend Firewall features are enabled."
Geo Fencing for vDefend
https://techdocs.broadcom.com/us/en/vmware-security-load-balancing/vdefend/vdefend-firewall/9-0/vdefend-gateway-firewall/geo-blocking-and-monitoring.html
VMware vDefend License Applied
https://techdocs.broadcom.com/us/en/vmware-security-load-balancing/vdefend/vdefend-firewall/9-0/vdefend-firewall-overview/getting-started-with-vmware-vdefend-.html