For retrieving router IP address on Mac OS below are the required steps.
In the top corner left of the screen on Apple icon Click
Click on “System Preferences…”in the menu
You must get a window with pop-up on System Preferences
On “Network” icon Click. To instantly find this icon Network window must pop up you can write its name in Search box.
Choose active connection in that. It is shown with green circle
On “Advanced…”Click
Choose IP/TCP/ tab in new Windows that will pop up
You must get a screen with info that will contain “Router:” entry in it. This is IP address of your router
By using terminal app getting router IP address.
At the foot of the screen in the menu click on Launch pad icon
In launch pad Type Terminal or obtain “Terminal” icon in a Launch pad icon list
On “Terminal” icon Click
Write netstat -nr | grep default In Terminal window
You must get a line of text appearing. Search for an IP address of your router afterword “default”. This is IP address of your router