If you're looking for a meeting place or a good stop around ½ or halfway between Shelbyville and Atlanta, you can try Dalton, GA, which is almost 2 hours southeast of Shelbyville, or about 1½ hours northwest of Atlanta.
About ¼ or a fourth of the way, you can stop at Bergmantown, TN. This is almost an hour east of Shelbyville.
About ⅓ or a third of the way, you can stop at Raulstontown, TN. This is almost an hour southeast of Shelbyville.
About ⅔ or two thirds of the way, you can stop at Calhoun, GA. This is a little over 2 hours southeast of Shelbyville, or a little over 1 hour northwest of Atlanta.
About ¾ or three fourths of the way, you can stop at Acworth, GA. This is about 2½ hours southeast of Shelbyville, or almost an hour northwest of Atlanta.
If you drive straight through without stopping at all, the total distance is 211 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 3 hours, 23 minutes.