How to route traffic from another router/gateway?

I’m doing a pentest and have ran an nmap scan which produces the following (the .85 IP is from gaining access to the server 1 machine and seeing it as it’s gateway):

Router/Gateway 1 - 192.168.193.85 Linux PC (mine) - 192.168.193.70 Windows server 1 - 192.168.193.211 Windows server 2 - 192.168.193.212 FTP server - 192.168.193.14

I have another IP on the network which is 192.168.193.4. No information about open ports/OS etc on it; same went for the router/gateway 1. I’m assuming the 192.168.193.4 IP is also another router. How can I gain access to the network behind that router? Thanks