At the time when they will check your application for family visit visa, before checking the documents attached with your application, they will check FIRST if you are INSIDE of Qatar; if by that time you will be already outside, they will not approve your application for following reason: for your family you are the sponsor and you cannot be consider as sponsor for the family, being outside of Qatar. So, try to be inside of Qatar during processing of your application and you can go outside after getting approval for your family