According to Sefaradim, if you make a Beracha one thing you don't make it another with the same Beracha (not for different forms though). What about rice? Rice, as we know has a different classification. So what's the Halacha there? Do you have to make another Beracha on the rice even if you made a Beracha on let's say a cake?
One of my Rabbanim (possibly a Posek) quoted Maran saying that if you had in mind the rice in the Beracha over other Mezonot (or vice versa) it is Poter the other food, however, according to Maran if he didn't have in mind it doesn't Poter. He mentioned that other Posekim disagree.
I assume the question means the following case.
A person had cooked rice and (let’s say) cooked oatmeal in front of him. He made the brocho BM”M on the rice and the question is whether this will cover the oatmeal.
There are two stages to the answer.
1) Rice is not so choshuv (important) as oats. As proof see the Mishna Berura 208 (7) where we see that a mixture of a minority of rice and a majority of another food takes the brocho of the other food. This would not be the case if the rice were replaced by one of the five species. In that case the brocho would be BM”M. The Mishna Berura says rice is not so choshuv.
2) Rabbi Bodner in his book “The Halochos of Brochos” chapter 7 C explains that a brocho made on one food covers the other “automatically” only when the other is less choshuv. He gives an example that a brocho made on a biscuit made of oats will not cover biscuits made of wheat because wheat is more choshuv than oats. If one deliberately intended to cover the less choshuv food, then it will be covered.
So it seems that the BM”M on the cooked rice will not cover the oatmeal unless he had specific intention to cover it.
But beware Hilchos Brochos is a minefield; ask a specific shaaloh to YLOR.