There are three sets of gallium halides, the trihalides where gallium has oxidation state +3, the intermediate halides containing gallium in oxidation states +1, +2 and +3 and some unstable monohalides, where gallium has oxidation state +1.
Read more about Gallium Halides: Trihalides, Intermediate Halides, Monohalides, Anionic Halide Complexes, General References