rental real estate is taxed by both your state of domicile (Illinois) and the state where the property is located (indiana). I'm not sure what the filing requirements are for non-residents of Indiana
you can find the instructions for non-residents here
https://www.in.gov/dor/tax-forms/2021-individual-income-tax-forms/
just like rental above a w-2 it's taxed by the state where you physically work and your state of domicile, if different, with some caveats.
they are:
a) some states have reciprocity with other states - you only pay taxes in the state of domicile. to avoid withholding or the need to file a return in the non-domicile state to get the taxes back withheld there is a form that can be filed with the employer. there is no reciprocity between Illinois and Indiana
b) telecommuting - some states tax the wages of a taxpayer who works remotely from an out-of-state location
if you pay Indiana income tax you can claim a credit on your Illinois return
