Notre entreprise possede une Licence valide de Coldfusion 7 MX qoui faire pour faire une mise à jour à Coldfusion 11

Sorry I can only answer in English.  I looked on the ColdFusion FAQ and you can only upgrade to ColdFusion 2016 from ColdFusion 10 or 11:

"Special upgrade pricing is available to those customers who have valid ColdFusion 10 or 11 licenses. Customers running ColdFusion 9 or earlier are not eligible for upgrade pricing."

Found here: Frequently Asked Questions (FAQ) | Adobe ColdFusion Enterprise (2016 release) ‌under "I already have a license for an earlier version of ColdFusion. What are my upgrade options?"