Hi Andrea and welcome to the forum,
This one is not in the support list. Therefore we need to connect to it using the tab for ONVIF Source or Custom URL. I don´t see that it support onvif so left is Custom URL as you already tested. I am not sure why you picked these URL´s but none of them seems to work.
In your support specifications I can see that RTSP/TCP use Port 8554. In your URL you use 554 so that is one reason why it not works. The question is also if the URL is correct? I did some search and found this information for this device from GeoVision:
So for NCS it should be using Custom URL,
Set Stream type to rtsp_tcp
Address is if admin/admin is correct
That should give you video and audio if the system support audio.
It seems that you have to login to the VS11 and setup the resolution.
Good luck and please report back how it goes.