I heard rumors that the actor who plays Kutner died in reality so that's the reason he died in the show-true or false?

No, he didn't. In fact, I've just posted a link to an interview with Kal Penn about why he left House (yes, he decided to on his own...it wasn't something forced on him sa pamamagitan ng the writers). He's going to work in the White House.

WHAT?! NO.