We see Rin get struck by chidori in her chest in the same spot as Obito. So why does Rin die when Obito doesn't?
Obito survived because he made himself the 10-tails Jinchuriki shortly after being struck by Kakashi
Both Rin Nohara and Obito Uchiha, who were branded with this cursed seal, had it removed by Kakashi Hatake's Chidori and Lightning Cutter respectively, although Rin died while Obito survived by sealing the Ten-Tails into himself shortly after.
As seen with other Jinchuriki, their tailed beasts provide them with healing abilities to survive wounds that would otherwise be fatal