A radius drawn around downtown buys clicks from three Indiana counties
Set geography by what you are set up to serve, not by a circle, because a few miles north of the Ohio River you are in a different state.
Clark and Floyd County are inside almost any sensible radius from central Louisville. If your business is set up to work only on the Kentucky side, that radius is buying inquiries you have to turn down, and you are paying full price for the privilege.
Use explicit locations rather than rings: Jefferson County, then the outlying Kentucky counties you serve, then Indiana as a deliberate decision with its own campaign. Set targeting to presence rather than interest so you stop paying for people researching Louisville from out of state.
Requirements differ between Kentucky and Indiana and they change, so confirm what applies to your business with the relevant state and local authorities and your own counsel before you advertise across the line. The ad account is not the place to find out.
If you do serve both sides, say so in the ad copy for the Indiana campaign. A New Albany homeowner who has been burned by a Kentucky company that would not cross the bridge will click the ad that removes the doubt.