The basic N6 description is that it leads to the dominant chord, but this doesn't fully explain its use in cadences.
A survey of my harmony texts - Piston, Seigmeister, and Kostka - show N6 going to dominant harmony as part of a perfect cadence. Or, the examples are too short to show how the phrases end cadence-wise.
I am mostly concerned with Baroque and Classical styles. Also, I'm not concerned with N6 in modulation or other non-cadence aspects.
Theoretically I suppose N6 could be used as part of a half-cadence, but I'm interested in its actual occurrence in scores. I lack the deep knowledge of the literature.