What Bluejets said is basically good advice. What's showing at the Keypad is that there is a Trouble condition (not an alarm) on that zone. If the Trouble won't reset at the keypad, then it's probably still in Trouble---whatever that means, for whatever device(s) is/are on whatever zone you're seeing it.
Troubleshooting will go a lot faster if you gave us more information.
Every alarm system, by its nature, is costomized. Not all zones are necessarily wired/configured the same, although they may be in your particular system.
Your Control Panel (the NX-6, not the Keypad) comes with 6 built-in on-board hardwired zones connected to the Control Panel terminal strip. A maximum of 10 extra zones can be added in 2 possible ways:
(1) Zone Doubling, which is a slightly more conplicated way to wire zones to the NX-6 with different value EOLRs (End of Line Resistors), or
(2)Wireless zones, which uses sensor/transmitter units that are (usually) white rectangular plastic boxes roughly 1.5 inches X 3 inches X 1 inch--unless your "trouble" zones is a motion or glassbreak sensor, which will look entirely different.
"Trouble" conditions on all these different type zones can be caused by different things each. So rather than draw up an eleborate "IF--THEN" logic tree, troubleshooting will go a lot faster if you tell what kind of zone it is, hardwired or wireless, and the ZONE NUMBER is often helpful. For instance, if you'd said (for instance) that you had a Trouble on Zone 15, Kitchen Window, then I'd have known immediately that it was a wireless zone and known the most likely thing to tell you to check for.
Knowing what the zone protects is also helpful. It the zone is a window, door, motion sensor, attic hatch, glassbreak sensor, smoke sensor, water heater overflow sensor, etc, etc, or what? Each type of sensor has something different to check for, in the case of a Trouble condition.
