Hey Ranbir! Once a domicile certificate has been issued or made is valid for life time, but these are state matters therefor it completely depends upon the state to provide any validity of certificate. If we talk about the GATE score card section in dte Maharashtra 's form, if you don't have a document to prove your result that means you didn't appeared for it without document you can't apply as during verification you will have to show the certificate. Hope this may help you.