"in the news" refers to when someone or some event is widely discussed in that subset of media we call "the news." "Simone Biles was in the news." This means that Simone Biles was discussed widely among news outlets, including television, radio, print, etc. "on the news" refers to when someone or some event is being reported on a television program that is classified as a news program. "Simone Biles was on the news." This means that Simone Biles appeared on a news show broadcast on television. I belive this is the general understanding in reagrds to these phrases. Hope it helps😊

"On the news" means that you specifically want to say that you saw it on television. "In the news" means that you want to say that you saw or heard or read it in general from any kind of news media, including television.

I would add that "on the news" often refers to television. "I saw it on the news" implies that you saw it on tv.