I'm 99% sure that the n 6.1 fits the k 6.1 and blx 6.1. I have it at home and the label does not indicate n 6.1 but fits.
I don't think Wilson changed their grommet patterns for the same model sucessors.
EDIT: Ok, I'm 100% sure now. I just check the website and the BLX 6.1/K 6.1 are the same grommets. When I ordered the Ncode 6.1 grommets, they gave me the K 6.1 grommets and they fit. They are all the same within the same model line and string pattern.