The highest rank you can achieve as NCO, your likely to have access to all specialized jobs in the Nu-7 'Autorifleman' and 'Marksman' and leading the operators on-duty, their duties is in your hand

this rank is only achievable for those who served atleast 14 months of service, he's well experienced in combat and trains operators 

this is the first entry rank into NCO, your likely to be mentored and it depends on your responsibility