Electron configuration of indium cation
Yup, it's $[\ce{Kr}]4d^{10}$.  Post-transition ($p$-block) elements rarely if ever ionize or even covalently bond their $d$ subshell electrons.  Although we use the bracketed core designation only for noble gas cores, by the time we get to Group 12 or 13 the $d$ electrons are also effectively part of the core.