No, the correct pattern for graphene transport is (1x Ny x Nz), assuming that y is the periodic direction.
K-points are used when a direction is periodic (and also in the transport direction). Exactly how big Ny should be depends on how delicate a property you are trying to model. But think that at least Ly/Ny > 25 Angstrom, where Ly is the size in the y-direction. This may not be enough, however, think of it as a convergence parameter.
Also, for graphene transport, use an odd number for Ny, since for some transport directions, this will make sure that the Dirac point is included in the calculation. This will improve the results.
