There are various commercial rice cookers available in the market today that can be used in restaurants. Panasonic SR-42HZP is one of the good ones. It has sheathed heating element that prevents heat loss. Once the rice is successfully cooked then the warming feature is automatically turned on.
Sharp KSH-777DW rice cooker is another good restaurant rice cooker that can be used for commercial purpose. It cooks rice really quickly. The time to cook the rice depends on the amount of rice. Usually it takes from 30 minutes to 60 minutes to finish the cooking
Here we mentioned only two commercial rice cookers that can be used in restaurants. It does not mean that these are the only ones. We just wanted to cite some examples of restaurant rice cookers. There are many other restaurant cookers available out there.