Well said by pantaz. Worst case might be to assume the beam is a cantilever. Therefore, even if bending about the minor axis, the bending stress on the global cross section would then be a mere 6.44 MPa, which is very little, assuming this beam is steel or aluminum. Holes near the neutral axis tend to be negligible. Large holes near the extreme fibers might be significant, if the beam were subjected to high bending stress, which currently appears to perhaps not be the case.
But as pantaz alludes to, the joint stresses might instead govern. Therefore, we probably need to see a dimensioned diagram of the assembly, boundary conditions, fastener material specifications, and bolt installation torque. azmo, is the given problem in post 1 a school assignment? Or not?