$(i)$ $\left[ FeF _{6}\right]^{3-}$
$(ii)$ $\left[ Co \left( NH _{3}\right)_{6}\right]^{3+}$
$(iii)$ $\left[ NiCl _{4}\right]^{2-}$
$(iv)$ $\left[ Cu \left( NH _{3}\right)_{4}\right]^{2+}$
$(I)\, [Ma_3b_2c]^{n \pm}\,\,\, (II)\, [M(AB)_3]^{n \pm}\,\,\, (III)\, [Ma_2b_2c_2]^{n \pm}$
$(I)\,\,\,-\,\,\,(II)\,\,\,-\,\,\,(III)$