The aim of this study is to introduce a new extended version of the GRA method for multi -criteria decision making method under the generalized fuzzy numbers. First, we develop some operational laws of credibility fuzzy numbers using the concept of Dombi norms and Bonferroni mean operator, furthermore we develop a series of aggregation operators and also discuss some basic properties like as; monotonicity , boundedness and assoicativity . Also, the core of this study is that we have developed two algorithms for multi -criteria decision making problems which is applied and to select the best option for the practical application example ( Telecom Company) of real life decision making problems. To check the validity of our developed method we have to compare with other existing methods.