You can have corals, but there is a risk that your anemone will walk around (they almost always do eventually) and sting everything in its path. This is particularly problematic for sps, since they grow onto the live rock and can't be moved out of the way. I learned this the hard way.
Some softies can also be a problem because of chemicals they release (colt corals, some leathers, and mushrooms).
The safest corals are probably LPS you can keep on the sand bed - plate corals, acans, etc. No chemical issues, and BTAs don't venture onto the sand.
Hope this helps.