Most trains bound for Tours, including all TGVs (as many as 10 per day), depart from Paris' Gare Montparnasse for the 1 hour 10 minute trip. A limited number depart from Gare d'Austerlitz. Many, but not all, of the non-TGV trains pull into the the main Tours station.Most TGV trains arrive at the isolated station of Tours/St-Pierre-des-Corps, about 6 km (4 miles) east of the centre of Tours. If you end up here, wait for the next navette train into Tours centre, grab a taxi, or await a free navette (bus) for ongoing transport to the centre of the city.
If you are coming down from Paris it may be an idea to travel down here by train and pick up your hire car here.