@anonymous OP - on RMS overview page, scroll down past Devices Map and click Device details icon under Action column. In subsequent page, on RHS under Mobile Details, you will see Mobile IP. That's it.
@ Vilmantas1 you have not understood the question properly I am afraid. The OP wanted to try and find the Public IP of the router through remote connection. The second link you have given is the interface when connected locally or, perhaps, when connected via the Web UI service of RMS - I don't know about the latter as I have tried the Web UI and although it says it is OK when "check availability" is clicked, the link does not connect but reports "An error has occured while trying to browse through the proxy.
Failed to connect to device. Possible problems are that the server was not found, the connection timed out, or the connection refused by the host. Try connecting again and check if the address is correct."
This Web UI error seems to be an oft reported problem recently with no solution that I can find.