Match the column:
Column−I Column−II(a)[Ag(NH3)2]+(p)Octahedral(b)[Cu(NH3)4]2+(q)Tetrahedral(c)[Cr(H2O)6]2+(r)Trigonal bipyramidal(d)[Fe(CO)5](s)Square planar (t)Linear
(a) → t; (b) → s; (c) → p; (d) → r.
Use CFT (or even VBT would suffice):
This above is the simplest of all, except maybe that [Ag(NH3)2]+ is linear!
The only complex with 6 ligands is the [Cr(H2O)6]2+ - which is clearly octahedral.
Cu2+ is 3d9 and thus has to be square planar! There are no tetrahedral complexes from the given 4.