Which it is the oxidation state of indium and phosphorus? I would like to know what the oxidation state of indium and phosphorus in a structure type rock salt. It could be +1 and -1? Yes or not? and why?

Thanks
I've estimated net atomic charges in rocksalt type InP by simple HF calculation in CRYSTAL06 in random basis.
Lattice parameter of 5.54 A is taken from:

K Kabita et al. First principle study on pressure-induced electronic structure and elastic properties of indium phosphide (InP). Indian J. Phys. (2015), DOI 10.1007/s12648-015-0701-0.

Results: http://pastebin.com/zdb8js8Z

Total atomic charges are 47.2861139, 16.7138861, so partial charges are:

In: +1.71
 P: -1.71


Given that oxidation state is an hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic, the answer is probably better estimated as +2/-2, not 1.