You have to dissolve Indium in hydrochloric or sulfuric acid.
2 In + 6 H+ => 2 In3+ + 3 H2
Thanks @chenbeier , but wouldn't i have to still get rid of the chlorine or sulfur
in the solution so they wont disturb the remaining process? I mean I believe
you don't really get In3+ as instructed, but InCl3 or so, isn't that right?