The release date hasn't been confirmed for either of them.
The main character in FFXIII is Lightning who has amnesia other characters include Mr 33cm and a red haired girl who's name hasn't been confirmed. The batte system will be real time and include tghe ATB system where each move will cost ATB points. The main worlds are Pulse and Cocoon.
The main character from Versus XIII is the Prince of a kingdom protecting the crystal which also gives him his powers his name hasn't been released yet. There is also another protagonist who name hasn't been given she is known as the girl with the Rapier at the moment. There are others with the Prince that haven't been named yet. None of the locations have been revealed yet. There's not much detail on the battle system but that they are going to have it like Final Fantasy Advent Children.
sig by Vasco
PSN ID: M-a-s-a-m-u-n-e