A person moves from their original place of residence to another place which we call as migration. What should we say if the person comes back to the same place after a while?
I think the word you are looking for is Repatriate
: to restore or return to the country of origin, allegiance, or citizenship
After living in Brazil for 14 years, John repatriated to the United States.
According to English Language Learners Dictionary: returnee : someone who returns to a place or activity; especially : someone who returns to a country after being in another country in prison, in military service, etc. The process of returning can be called: return, coming back, comeback, homecoming. For example: HOMECOMING - Your homecoming is your return to your home or your country after being away for a long time (CollinsCobuild). COMEBACK - a return to a former position or condition (Merriam-Webster's).