The calculated distance (air line) between Voisins-le-Bretonneux and Rennes is approximately 177 miles respectively 284 kilometers.
By car or train, the actual journey to Rennes is certainly longer, as only the direct route (as the crow flies) between Voisins-le-Bretonneux and Rennes has been calculated here.
Air line (approximately)
284 kilometers
153 nautical miles