  We study the quantum correction to conductivity on the surface of cubic
topological Kondo insulators with multiple Dirac bands. We consider the model
of time-reversal invariant disorder which induces the scattering of the
electrons within the Dirac bands as well as between the bands. When only
intraband scattering is present we find three long-range diffusion modes which
lead to weak antilocalization correction to conductivity, which remains
independent of the microscopic details such as Fermi velocities and relaxation
times. Interband scattering gaps out two diffusion modes leaving only one
long-range mode. We find that depending on the value of the phase coherence
time, either three or only one long-range diffusion modes contribute to weak
localization correction rendering the quantum correction to conductivity
non-universal. We provide an interpretation for the results of the recent
transport experiments on samarium hexaboride where weak antilocalization has
been observed.
