This link has a downloadable map of the route through Caen (Calvados department in Normandy) for stage 6 on July 7 (click on 'Tour de France, carte de l'itinéraire routier et déviations' at the bottom of the page).

It includes the route, road closures and deviations (and hence feeder roads to the route if you're a spectator).

In summary, the (French) text says:
– The Tour will use 113 km of the Calvados department's roads. The riders and the caravan enter the department at Champ-du-Boult and then on to Vire, Vassy, Pont-d'Ouilly, Condé-sur-Noireau, Falaise, Morteaux-Couliboeuf and Livarot before arriving at the finish in Lisieux.
– This route will be closed to motor traffic from 10am and reopen after the passage of the riders.
– Yellow road signs are being erected on all roads hat will be affected.