use granite/ui/components/coral/foundation/form/selectrather than granite/ui/components/foundation/form/select. If it does'nt work.You can try to overlay the /libs/granite/ui/components/coral/foundation/form/select/render.jsp and add some log in the key line which render the selected item.

Hi, prash0905Which version of AEM are you using?I remember that I have met this issue before when using the early version.

If you are using the AEM On-Premise.You can customize the naming conventions by overlay the fileupload.js.