When did the Tyrannosaurus Rex die?

About 65 millon years ago. It was one of the last dinosaurs to live.
Most dinosaurs, including tyranosaurus rex, died off about 65 million years ago.

Most life on Earth ended 65-66 million years ago during what is called the Cretaceous–Paleogene extinction event.

There is substantial scientific evidence of an asteroid impact on Earth that caused or was a significant contributor to the extinction.

Some dinosaurs (the theropods) probably are still around - we call them birds