The IUPAC name of the Wilkinson’s catalyst \([RhCl(PPh_3)_3]\) is

Chloro tris (triphenyl phosphine) rhodium (I)

The correct answer is option 1. Chloro tris (triphenyl phosphine) rhodium (I).

The oxidation state of the metal ion in Wilkinson's catalyst is +1, so the name of the compound must end in "(I)". The ligands in Wilkinson's catalyst are triphenylphosphine, which is a neutral ligand, so the name of the compound must start with "tris". The oxidation state of the metal ion is written in parentheses after the name of the ligand.

Therefore, the correct IUPAC name of Wilkinson's catalyst is tris(triphenylphosphine)chlororhodium(I).