is reits considered as real estate under GIPS?

unlikely because they are traded on an exchange and have daily price quotes

no they’re not considered part of pe or real estate in GIPS. only direct real estate is afaik

the standard is only about correct valuations and hence direct real estate is the only one that’s given importance?

I just read GIPS. REITs and MBS are NOT considered real estate.

Moreover, for Private Equity, P.E. open end funds and Evergreen funds are NOT considered private equity.

It’s not just direct real estate. There are other forms listed. Just know that REITs and MBS are not real estate.