Which of the following compounds has a different geometry from the others?

Which of the following is/are correct for the complex $[Cu(NH_3)_4]^{2+}$?

The number of species from the following that are involved in $sp^3 d^2$ hybridization is $[Co(NH_3)_6]^{3+}, SF_6, [CrF_6]^{3-}, [CoF_6]^{3-}, [Mn(CN)_6]^{3-}$ and $[MnCl_6]^{3-}$.

Using valence bond theory,explain the following in relation to the complexes given below: $[Mn(CN)_{6}]^{3-}, [Co(NH_{3})_{6}]^{3+}, [Cr(H_{2}O)_{6}]^{3+}, [FeCl_{6}]^{4-}$
$(i)$ Type of hybridisation.
$(ii)$ Inner or outer orbital complex.
$(iii)$ Magnetic behaviour.
$(iv)$ Spin only magnetic moment value.

Geometrical shapes of the complexes formed by the reaction of $Ni^{2+}$ with $Cl^{-}$,$CN^{-}$,and $H_2O$,respectively,are

The type of hybridization involved in the metal ion of the $[Ni(H_2O)_6]^{2+}$ complex is: