That is a private address. If you want the modem to communicate with your ISP it needs to have a public address, most likely a dhcp address assigned by your ISP. You need to call your ISP and have them help you with the modem.
It seems you are able to access the internet if you connect the PC to the modem but you cannot if the router is connected between the modem an the PC.
is your problem that you cannot connect to the internet via router?
Connect the router to PC via network cable (modem needs to be disconnected from router), login to the router via 192.168.1.1, and change the LAN IP to 192.168.2.1, save the settings, connect the modem to the router, and reboot your router.