If your camera is not listed and you already tried selecting all the Other Camera possibilities, then search the camera's maker homepage for the GET Request Format. Enter the found GET-COMMAND in the Connect To dialog as an URL:
For example axis cameras use for RTSP (with default port 554):
or for HTTP jpeg snapshots (with default port 80):
and for HTTP motion jpeg (with default port 80):
Remember to replace IP with the camera's IP address.