How did Parisians view Le Corbusier's "Radiant City" design for the center of Paris, proposed in the 1920s? Why was it rejected? Did it have any supporters?

Are you referring to Le Corbusier's Plan Voisin?

The Plan Voisin was a 1925 proposal to redevelop the center of Paris that applied many of the principles set forward in his 1922 project the Ville contemporaine pour trois millions d'habitants. The Radiant City (Ville radieuse) was Le Corbusier's utopian project for an entirely new planned city from 1930.