For an octahedral complex $\left({\mathrm{d}}^4 \mathrm{configuration}\right)$ with ${∆}_0<\mathrm{P}$ the electronic arrangement is

${∆}_0<\mathrm{P}$means that it is a complex of weak field ligand.  Energy of ${\mathrm{t}}_{2\mathrm{g}}< {\mathrm{e}}_{\mathrm{g}}$

For  ${\mathrm{d}}^4$ configuration, first three electrons enter into ${\mathrm{t}}_{2\mathrm{g}}$ level and the fourth electron goes into ${\mathrm{e}}_{\mathrm{g}}$level,  ${\mathrm{t}}_{2\mathrm{g}}^3 {\mathrm{e}}_{\mathrm{g}}^1$