Assuming you're talking about cooked rice, plain, in a sealed container with a minimum of air inside, it will probably last at least one week - smell it and check it for mold or anything like that after that, it may be good a little longer than that.
Depending on how it's stored (unsealed containers e.g. bowl with cellophane or tinfoil) or if there's something mixed in there, however, it could be as little as 2-3 days.