It is unknown if Tommy Vercetti is alive because he was last seen from us in 1986 in Grand Theft Auto Vice City, and mentioned in Grand Theft Auto: San Andreas' prologue. It can however be assumed that he and all people from the Grand Theft Auto III era are dead as they are never seen or heard from again after Grand Theft Auto III, set in 2001. In Grand Theft Auto IV there is an easter egg in the apartments district that states that men named Vic, Victor, Carl, Toni, Claude, & Tommy are all dead as they are written about in the past tence. As you can tell, the names of these men are all the names of the protaganist characters in the GTA series. Obviously Victor "Vic" Vance (In the easter egg he is mentioned twice) was dead by 1986 so with the excuse of him, everyone else was alive by 2001 so the easter egg would hint to the fact that they are all dead.