Yes, of course, but you should better use separate threads for that. Your listening thread needs to use blocking calls to listed, and a thread already having a connection and writing to a network stream or reading from it is blocked by write or read operations. So each such activity should be done in a separate thread.
It also depends on your application-layer protocol (always try to define such protocol explicitly). Typically you have a protocol which requires you to read and write in certain regular order, then such read and write operations, being sequential, will be done in a single thread; but not in the same thread where you listen. The port is irrelevant here. If you add some activity on one port, your threads should be separate from those using another port. At the same time, another (somewhat typical) mistake would be using a separate thread per client. On the server side, all clients should better be served with one thread, but listening thread should be separate, of course.
Please see my past answers:
an amateur question in socket programming
Multple clients from same port Number
How Do I Get To Know If A A Tcp Connection Is Over