you have to file 2 state returns. one is as an Indiana non-resident - this state return must be completed first in TT. Then you finish IL resident return where the CR form should compute the credit for the double-taxed income. when you e-file IL - TT should send an electronic copy of In along with the IL return and if you e-file In a copy of that return goes there. before filing make sure that for the CR form all your wages are in Column A and only In wages are in Column B. in addition there may be certain amounts for other lines that may have to be pro-rated.
note that we can not see your w-2 or tax return. ,
see these instructions for the Cr form to determine what items may be affected
https://www2.illinois.gov/rev/forms/incometax/Documents/currentyear/individual/il-1040-schedule-cr-i...
