$[Co(NH_3)_4Cl_2]NO_2$ and $[Co(NH_3)_4Cl.NO_2]Cl$ are $........$ isomers.

For an octahedral complex $MX_{4}Y_{2}$ ($M=$ a transition metal,$X$ and $Y$ are monodentate achiral ligands),the correct statement among the following is

Which of the following complexes is paramagnetic?

Which among the following metal complexes exhibits optical activity? ($AA$ = bidentate ligand; $A, X$ = monodentate ligands)

The complex compound $[Cr(NCS)(NH_3)_5][ZnCl_4]$ will be:

In which of the following orders are the given complex ions arranged correctly with respect to their decreasing spin-only magnetic moment?
$(i)$ $[FeF_{6}]^{3-}$
$(ii)$ $[Co(NH_{3})_{6}]^{3+}$
$(iii)$ $[NiCl_{4}]^{2-}$
$(iv)$ $[Cu(NH_{3})_{4}]^{2+}$