Identify the correct IUPAC name for the complex.

\([(Co(H_2NCH_2CH_2NH_2)_3]_2 (SO_4)_3\)

tris (ethane-1,2-diamine) cobalt(III) sulphate

The correct answer is option 3. tris (ethane-1,2-diamine) cobalt(III) sulphate.

The correct IUPAC name for the complex \([(Co(H_2NCH_2CH_2NH_2)_3]_2(SO_4)_3)\) is: (3) tris(ethane-1,2-diamine)cobalt(III) sulphate

1. Metal Center:  Cobalt is the central metal ion.

2. Ligand: The ligand is ethane-1,2-diamine, which is also known as ethylenediamine (en). The complex has three ethylenediamine ligands.

3. Coordination Number: Cobalt is coordinated to three ethylenediamine ligands, so the coordination number is 3.

4. Oxidation State: Cobalt is in the +3 oxidation state, as each ethylenediamine ligand contributes a neutral charge, and there are two cobalt ions in the complex.

5. Counterion: The counterion is sulfate \((SO_4)^{2-}\).
   
Putting it all together, the correct IUPAC name is tris(ethane-1,2-diamine)cobalt(III) sulphate.