The number of manganese ions in tetrahedral and octahedral sites, respectively in $\mathrm{M}{\mathrm{n}}_3{\mathrm{O}}_4$ are one $\mathrm{M}{\mathrm{n}}^{2+}$ and two $\mathrm{M}{\mathrm{n}}^{3+}$ ions.
$\mathrm{M}{\mathrm{n}}_3{\mathrm{O}}_4$ has spinal type structure in which $\mathrm{M}{\mathrm{n}}^{2+}$ occupy 1/8 T.V. and $\mathrm{M}{\mathrm{n}}^{3+}$ occupy half of O.V.
Oxide ion has ccp arrangement (corner + face).