Which of the following species does not have all types of bond length same?

Axial and equatorial bond lengths for ${\mathrm{ClF}}_3$ are both two. Due to the trigonal-bipyramidal (${\mathrm{sp}}^3\mathrm{d}$-hybridization) shape of the ${\mathrm{ClF}}_3$ molecule, not all bonds in this compound are equal.