Indium halides
There are three sets of indium halides, the trihalides, the monohalides and a surprising number of intermediate halides. In all of the trihalides the oxidation state of indium is +3 and their proper names are indium(III) fluoride, indium(III) chloride, indium(III) bromide and indium(III) iodide. 
In the monohalides the oxidation state of indium is +1 and their proper names are indium(I) fluoride, indium(I) chloride, indium(I) bromide and indium(I) iodide.
The intermediate halides contain indium with oxidation states, +1, +2 and +3.

# Indium trihalides
All four trihalides are known. The trihalides are all Lewis acids. Indium trichloride is a starting point in the production of trimethylindium which is used in the semiconductor industry.

# Intermediate halides
There are a surprising number of intermediate chlorides and bromides, only one iodide, InI2, and no fluorides. The first intermediate halides found were the dihalides where indium has an apparent oxidation state of +2. These were actually found to contain indium in the +1 and +3 oxidation states and to be formulated as InIInIIIX4. It was some time later that the existence of compounds containing the anion  In2Br62 were confirmed which contains an indium-indium bond. Early work on the chlorides and bromides involved investigations of the binary phase diagrams of the trihalides and the related monohalide. Many of the compounds were initially misidentified as many of them are incongruent and decompose before melting. The majority of the previously reported chlorides and bromides have now either had their existence and structures confirmed by X Ray diffraction studies or have been consigned to history. Perhaps the most unexpected case of mistaken identity was the surprising result that a careful reinvestigation of the InCl/InCl3 binary phase diagram did not find InCl2. 
The reason for this abundance of compounds is that indium forms 4 and 6 coordinate anions containing indium(III) e.g. InBr4, InCl63 as well as the anion In2Br62 that surprisingly contains an indium-indium bond.

# Monohalides
The solid monohalides InCl, InBr and InI are all unstable with respect to water, decomposing to the metal and indium(III) species. They fall between gallium(I) compounds, which are more reactive  and thallium(I) that are stable with respect to water. InI is the most stable. Up until relatively recently the monohalides have been scientific curiosities, however with the discovery that they can be used to prepare indium cluster and chain compounds they are now attracting much more interest.

# Anionic Halide complexes of In(III)
The trihalides are Lewis Acids and form addition compounds with ligands. For InF3 there are few examples known however for the other halides addition compounds with tetrahedral, trigonal bipyramidal and octahedral coordination geometries are known.
With halide ions there are examples of all of these geometries along with some anions with octahedrally coordinated indium and with bridging halogen atoms, In2X93 with three bridging halogen atoms and In2X7 with just one.
Additionally there are examples of indium with square planar geometry in the InX52- ion. The square planar geometry of InCl52 was the first found for a main group element.

# Anionic halide complexes of In(I) and In(II)

# Neutral Indium(II) halide adducts
Following the discovery of the In2Br62- a number of related neutral compounds containing the InII2X4 kernel have been formed from the reaction of indium dihalides with neutral ligands.Some chemists refer to these adducts, when used as the starting point for the synthesis of cluster compounds as In2X4 e.g. the TMEDA adduct. 

# General References
- WebElements

# Footnotes
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