Answer
See explanation below.
Work Step by Step
Two electrons occupy two separate eg orbitals and both remain unpaired in an octahedral d8 complex.Whereas the electrons occupy all other levels and fill them except the (dx2-y2) orbital, which is unoccupied in square-planar d8
complex.Because of which octahedral d8 complex is paramagnetic in nature and
square -planar d8 complex is diamagnetic in nature.