Please see this link for guidance on how to prepare your state amended return to claim the credit for the taxes paid in Ohio.
When you start the process of amending, you will need to make the entries in the state interview section of the program. Proceed through the screens until you see the screen titled "Take a look at Indiana credits and taxes" and select start/revisit to the right of Credit for Non-Indiana Local Taxes. Proceed to answer the questions on each screen to generate the credit.