It will all depend on what your routers are and the firmware they are running. With third party firmware such as DD-WRT, you can change the security settings on the 192.168.9.3 router. Specifically you want to enable management from the WAN port (under the "Administration"->"Management" tab).
For some other third party firmware and some first party firmware, you will need to add a firewall rule on the 192.168.9.3 router to allow connection, typically something like the following assuming it is using iptables as the firewall in the firmware:
iptables -I INPUT -p tcp -s <remote_location_ip> --dport 80 -j ACCEPT
Not all first party firmware will allow these kinds of changes, which is why I always recommend only buying a wifi router that supports running third party firmware such as DD-WRT, OpenWRT, or FreshTomato.
You will also need to setup static routes on all your routers so they know where to send the various traffic (i.e. the 192.168.9.2 router needs to know to send the traffic to 10.0.0.0 subnet out the WAN port, the 192.168.9.1 needs to know to send data to the 10.0.0.0 subnet to the port connected to the 192.168.9.3 router, and to send traffic to the 10.0.1.0 subnet to the port connected to the 192.168.9.2 router, and the 192.168.9.3 router needs to know to send traffic to the 10.0.0.0 subnet out the WAN port).