  Proton decay in six dimensions orbifolded on square $T^2/Z_2$ is highly
suppressed at tree-level. This is because baryon number violating (BNV)
operators containing only the zero mode of bulk fermions must satisfy the
selection rule $\frac{3}{2} \Delta B \pm \frac{1}{2}\Delta L = 0 \ mod \ 4$. In
this article, we show that the above relation does not prohibit mass
dimension-6 BNV operators containing Kaluza Klein (KK) partners of the bulk
fermions. Together with `spinless' adjoint scalar partner of hypercharge gauge
boson (the Dark Matter candidate), these novel operators generate Dark Matter
assisted proton decay at mass dimension-8. Here, with explicit examples of
scalar and vector baryon number violating interactions, we discuss the
importance of such $\Delta B=1 =\Delta L$ and $\Delta B=2=\Delta L$ operators
and derive the limit on New Physics.
