Both.
For Marvel Comics, it's 199999. They gave this designation back in 2008 in the early days of the MCU.
Once the MCU started exploring the Multiverse +10 years later, I think Marvel Studios chose not to follow the idea that "comics and movies co-exist in the same multiverse", making the MCU a separate multiverse (?). In one way or another, 616 is the only designation mentioned in MCU movies/shows.
