According to https://en.wikipedia.org/wiki/List_of_best-selling_video_game_franchises GTA and CoD are both at 250 million.
Its Wiki, but I get where you are coming from. CoD might make in a few more years or so then. Though it would depend on how burned out consumers are with CoD over time. GTA might make it once GTA VI makes it out of PS4/Xbone.