We need to know the "Connect Tone" for this system. Someone can give you the NAC code.
[From the RR Wiki]
To determine the NAC for a P25 voice-capable Motorola trunked system:
1. Start with the system ID in hexadecimal format.
2. Take the right side (lower) two hex digits.
3. Add the connect tone index number to right side (see list above).
4. You now have a 3-digit hex NAC. http://wiki.radioreference.com/index.php/Motorola#Connect_Tones
(2) Trunked NAC exists on the frequency for the trunk system, not the talkgroup. NACs do not change on a trunk system from talkgroup to talkgroup. Every frequency at a given site is going to have the same NAC, regardless of what talkgroup it's currently carrying.
If the TRS is a P25 Trunk or has P25 TG's there is a NAC, typically not needed for Scanning, unless a.) For Reference when searching manually b.) For monitoring specific freqs that are P25 Only on an older TRS