Both [Ni(CO)$$_4$$] and [Ni(CN)$$_4$$]$$^{2-}$$ are diamagnetic. They hybridisations of nickel in these complexes, respectively, are :

The IUPAC name of [Ni(NH$$_3$$)$$_4$$] [NiCl$$_4$$] is :

Statement 1 : [Fe(H$$_2$$O)$$_5$$NO]SO$$_4$$ is paramagnetic.

Statement 2 : The Fe in [Fe(H$$_2$$O)$$_5$$NO]SO$$_4$$ has three unpaired electrons.

Statement 1 : The geometrical isomers of the complex [M(NH$$_3$$)$$_4$$Cl$$_2$$] are optically inactive.

Statement 2 : Both geometrical isomers of the complex [M(NH$$_3$$)$$_4$$Cl$$_2$$] possess axis of symmetry.