It depends. There are many, many types of reits. There are mortgage reits (which buy up paper that pays interest) and equity reits (which own properties/have mortgages themselves). Mortgage reits payout depends on the rate of paper and their ability to resecuritize/recollateralize debt for capital gain (the repackaging of different risk-rated securities and unrated securities into new securities). Equity Reits payout based on their rental income. 

Within equity reits, there are many flavors: industrial (factories), biotech (labs, manufacturing), server farms, hospitals, residential (apartments) and commercial (office space). Each have their own risks and average yields.
That said, its not unreasonable to get 6-12% yield on a specific REIT. 

REITs are a decent alternative source of income. Just remember, if you already own a house a HUGE portion of your investment portfolio is already in Real Estate. Unless you rent or have a lot of other investments, adding REITs to your portfolio can be redundant on your largest investment. They also can have relatively high expense ratios (since someone is actively managing a real estate portfolio).

If you have more questions call me at 813 964 7100 or email me at mminter@mintcofinancial.com