You have successfully added the virtual interfaces, you are having trouble adding the network to the routing table.
Possibly missing out some of these steps caused some confusion.
route command error messages
Error : SIOCADDRT invalid argument
SIOCADDRT is an error message ADDing a RouTe.
"invalid argument" normally comes from missing something out. The line:
route add -net 192.168.0.0 netmask 255.255.255.0
looks fine though. Is there anything else to the error message?