What other characters are alive when the game makers change the rules so that people from the same district can survive?

In "The Hunger Games," when the game makers announce the rule change allowing two tributes from the same district to survive, Katniss Everdeen and Peeta Mellark from District 12 are the primary characters affected by this change. Other tributes, including Rue and Thresh from District 11, are also alive at that point, but they do not benefit from this rule change since they are from different districts. The rule change ultimately sets the stage for Katniss and Peeta's alliance and their defiance against the Capitol.