In which year first 3D video game released to the public

It depends on what you qualify as 3D, and whether you are talking strictly console games or computer games as well. Earlier "3D" Video games were actually Isometric, which is more of a "2.5D". The first truly 3D console video game, complete with polygonal characters as opposed to 2D sprites on a 3D background was probably released around 1995/1996