In the complex, KyCoC2O4zClx the values of x, y, z respectively are
3, 2,1
4, 1,1
2, 3, 2
2, 4,1
Coordination number of Cobalt(III) is six;
Oxalato is a bivalent negative ligand;
Chlorido is a monovalent negative ligand;
So the complex is K3CoC2O42Cl2