Opening a support case (or a so-called "Service Request", SR) assumes that you are a so-called Read/Write Contact of your "support project". If you don't know what that means, then please ask your in-house Informatica administrator who is the Primary Read/Write Contact; this person can either enable you as another Read/Write Contact or can raise the SR with Informatica Global Customer Support (GCS).
If you are the Informatica administrator, then you should have a link named "Access eSupport" at the left edge of the Quick Links; these Quick Links are displayed on the home page of the Informatica Network once you've logged on there.
If you don't have this link Access eSupport, then you have to look for the phone number of the nearest GCS Support Center near you and call them.
I know this is a whole lot of details. Please refer to the respective GCS guidelines (to be found following the link Support Documents in the box at the left edge of the Informatica Network home page, under the heading GCS Policies And Procedure Guide) for all those details. This GCS Policies document is always the point where such things are (hopefully) explained in detail.
Thanks for your response ! Yes, i am an Administrator but i do not find "Access esupport" in the homepage . Does calling client It support would help ?
The question is whether you are listed as a Read/Write contact for your organisation. When you call GCS via phone, they can tell you who is registered as Read/Write contacts. This way you should be able to find out whom to contact internally.