Hi shahid khan,
To open my router, I simply type:
http://192.168.1.1 into the address bar of my browser. This should bring up a login window for the router into which you would type
the user name: admin, and then the admin's password: <default admin password>.
Upon installation, there is a <default admin password> which if you do not know it, you should consult the manufacturer's documentation for your router on the manufacturer's web site unless you have a CD from the installation which should contain the information. If you changed it after installation, then hopefully, you recorded it somewhere.
-- Tom