The IPTV channel list file will be [based on my 6141-pro] a .m3u file. A playlist file essentially containing links to servers that have the channel stream.
Search on internet for IPTV m3u, yu may find many. The lists play on vlc player generally BUT that doesnt mean all that is playable on the STB. Many channels return error as "Data error".
The IPTV list name had to be "tvlist" with ".m3u" as file extension. This file should be in the root folder of the pen/usbdrive. You may find "Import" option when you are in IPTV application's channel list.
For 6363, there may be changes but you can start with above info. You tube does have user videos demonstrating this for many make/models.
The not so entertaining part of is that the IPTV stream servers somehow keep changing. Some channels disappear in a day, some in few days. You have keep searching for updated list [or learn how to loacte the servers!]. Otherwise, IPTV in my experience, is not very reliable.
EDIT: Add :
Have you bought a compatible USB wifi adapter?? Otherwise no internet access to STB.
Regards,
Kiran