\({Ni}^{+4} \rightarrow {d}^{6}\) strong field ligand
\([image(1)]\)
Pairing will be there zero unpaired electron
\({NiCl}_{2} \rightarrow {Ni}^{2+} \rightarrow {d}^{8}\)
\([image(2)]\)
Change \(=2\)
$A: \left[ Ni ( en )_{3}\right]^{2+}, B :\left[ Ni \left( NH _{3}\right)_{6}\right]^{2+}, C :\left[ Ni \left( H _{2} O \right)_{6}\right]^{2+}$
$(A)\,\,\,\,[Ni(H_2O)_5NH_3]^{2+},$
$(B)\,\,\,\,[Ni(H_2O)_4(NH_3)_2]^{2+}$
$(C)\,\,\,\,[Ni(H_2O)_3(NH_3)_3]^{2+}$