Most people consider REITS as part of thier stock allocation.
Some advocate holding REITs in total market index funds only, while others advocate a larger percemtage by holding an individual REIT or REIT index.
Proponents of increasing REIT exposure usually cite the proportion of real estate held in private equity or using it as an asset with less correlation to US stocks to better diversify. Others might argue the additional diversification is not warranted, adds complexity, and increases risk by overweighting a single sector.
As for what is right for you, only you can answer that. You can check various calculators like cfireism or portfoliocharts to run the allocation through historical data, however, the data does not go back very far as REITS are relatively new, and the past is not predictive of the future.
Personally I overweight REITs, but that is just a preference of mine and may end up helping or hurting me in the long run. Most famous proponent is Swensen who manages the Yale endowment. He recommends 20% of total allocation in REITs.
https://portfoliocharts.com/portfolio/swensen-portfolio/