As the lobes of dx2-y2 point towards the ligands, this orbital has the highest energy. The lobes of dxy orbital lie between the ligands but are coplanar with them this orbital is the next highest energy. The lobes of dz2 orbital point out of the plane of the complex but the belt around the centre of the orbital (which contain 1/3 of the electron density) lies in the plane. Therefore dz2 orbital is the next highest in energy. The lobes of dx2 and dy2 orbitals point out of the plane of the complex. Hence, they are least affected by the electrostatic field of the ligands. They are degenerate and lowest in energy.
