When I've used rice, I've used Minute Rice (which worked great!) or done a cereal mash with cooked rice before adding it to my mash.
As long as the rice is gelatinized through making it flaked, cooked (like the cooking I did and the cereal mash) or parboiled like Minute Rice, I don't think it would matter at all.
If Bob will let me have some of our hard-earned wild rice, I plan on doing a wild rice lager and I'll just cook the wild rice first. (I know that wild rice isn't a rice, it's a grass seed, but it's treated the same way in cooking and mashing!)