The difference in energies of two sets of d-orbitals $t_{2g}$ and $e_{g}$ is calledcrystal field splitting energy ($\Delta_{o}$).(i) If $\Delta_{o}$ < P, the configuration will be $t^{3}_{2g}e^{1}_{g}$ and it is there in case of weakfield ligands and high spin complex will be formed.(ii) If $\Delta_{o}$ > P, the configuration will be $t^{4}_{2g}e^{0}_{g}$ and it is in case of a strong fieldligands and low spin complex will be formed.