Hybridisation of the central atom can be calculated as:
H=
1
2
[(No. of valence electrons in the central atom)+(No. of monovalent atoms around central atom)−(Charge on cation)+(Charge on anion)]
After calculation of hybridisation of the central atom we find that all the given species except [SbCl5]2− have central atom with sp3d (corresponding H =5) hybridization, In [SbCl54]2−,Sb is sp3d2 hybridized.