The system will typically only look in specific paths for fonts. On my machine these are /usr/share/fonts, /usr/local/share/fonts, and the user's own ~/.fonts directory. Ubuntu may do it differently, but you could look for a file fonts.conf in the /etc directory or a subdirectory and read it.

Try putting the ttc file into ~/.fonts, running fc-cache ~/.fonts, then running fc-list | grep -i yourfontname to see if your font is there.