Will Niko Bellic ever show up
Taliban-E-Beabdi
Both GTA 4 and GTA 5 are set in the same HD Universe. That means characters from both games live in the same continuity. Several GTA 4 characters have shown up in GTA Online, the multiplayer counterpart to GTA 5, and players will likely encounter Brucie Kibbutz or Tony Prince in some fashion.
However, Niko Bellic has yet to make his return to the series. GTA Online is the latest game in the timeline, yet he is nowhere to be seen. Players can't be blamed for giving up that hope a long time ago, as it is dependant on Rockstar's current relationship with Niko's voice actor.