[ N i C l 4 ] 2 - , [ P t C l 4 ] 2 - and [ P d C l 4 ] 2 - are respectively :-

Step-by-step solution

[ N i C l 4 ] 2 - → Ni is 3d series element → C l - weak ligand → High spin [ P d C l 4 ] 2 - → Pd is 4d series element → Low spin [ P t C l 4 ] 2 - → Pt is 5d series element → Cl − act as strong field ligand for Pt and Pd as they are 5d, 4d elements respectively with high effective nuclear charge.