The Grande Ecole programme and the Master in Management are the same programme.
The admission conditions are different depending on your background.
If you have completed a preparatory class for the Grandes Ecoles: You are eligible for the Grande Ecole programme, via the BCE entrance exam. You will begin this programme in Licence 3.
If you have a minimum of two years of higher educaton approved by the French Ministry of Higher Education, Research and Innovation or a minimum of a level II certified RNCP title: You are eligible for the Grande Ecole programme, via the AST entrance exam. You will start the programme in Licence 3 (AST1 entrance exam) or in Master 1 (AST2 entrance exam).
If you have an international degree and have spent at least two years abroad for your higher education: You are eligible for the Master in Management (MIM) programme, via the ASTi or Join a School in France competitive entrance exam, and you will enter this programme in Master 1.