The calculated distance (air line) between Saint-Pryvé-Saint-Mesmin and Rennes is approximately 165 miles respectively 265 kilometers.
By car or train, the actual journey to Rennes is certainly longer, as only the direct route (as the crow flies) between Saint-Pryvé-Saint-Mesmin and Rennes has been calculated here.
Air line (approximately)
265 kilometers
143 nautical miles