This post explains how to login directly to Admin Console for WebSphere Portal 6.x and Integrated Solutions Console for WebSphere Portal 7.x
This IBM Technote article explain these information and you can look for either serverindex.xml (or) as simple as you can look at the Portal SystemOut.log and search for the below entry
1. TCP Channel TCP_1 is listening on host * (IPv4) port
Note: TCP_1 is called as WCInboundAdmin
For WebSphere Portal 6.x - [URL]:10027/admin
For WebSphere Portal 7.x - [URL]:10042/admin
