This paper reports on studies into the controllability of the regional income disparities and redistribution allocation of regional investment arising from the modified Rahman Type Model using the concepts of fuzzy numbers in fuzzy set theory and the optimistic and pessimistic optimal solutions. One theorem and six corollaries and the detailed simulations concentrating on the controllability of minimum proportion of investment and redistribution allocation of regional investment are discussed. The Fuzzy Regional Growth Model represents relatively easy-to-implement system with an fuzzy condition which can be extended to a variety of disparities and redistribution allocation of regional investment among systems of regions.