If you're looking for a meeting place or a good stop around ½ or halfway between Shelbyville and Columbus, you can try Louisville, KY, which is a little over 3 hours north of Shelbyville, or about 3½ hours southwest of Columbus.
Another possible place to stop near the midpoint is Jeffersontown.
About ¼ or a fourth of the way, you can stop at Bowling Green, KY. This is about 1½ hours north of Shelbyville.
About ⅓ or a third of the way, you can stop at Glasgow, KY. This is about 2 hours north of Shelbyville.
About ⅔ or two thirds of the way, you can stop at Florence, KY. This is about 4½ hours north of Shelbyville, or about 2 hours southwest of Columbus.
If you drive straight through without stopping at all, the total distance is 436 miles. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 6 hours, 38 minutes.