The first number before the dash is the P25 band plan number and the second number after the dash is the LCN.
You can figure out the frequencies from the band plans tab if it decoded and populated the band plans properly, but if it did then you would already have the correct frequencies and not 0.
I can't tell which Unitrunker window is this? Is it the call history window? Are these 0 frequencies all voice channels on the same site or is this on the system channels window?
Does MARCS have any other bands besides 700/800 MHz? If it's only 700/800 I can't see a system like that having 12 band plans so looks like maybe bad decoding. You could try deleting the 0 frequency channels, delete the band plans on the site window for that site, and let everything repoplulate.