FF7 was never gonna be on N64, a cartridge based console that launched in 1996, 2 years after the PS1 and Saturn.
FF7 was also never meant as a PS1 game only, Square needed the CD format to make the game happen, it would've come out on the Sega Saturn day 1 as well if the system wasn't so hard to develop for. Sega (which was pioneering 3D at arcades) making a 2D based console with exotic, expensive hardware is what lead to their ultimate demise. Exotic hardware>harder to develop on/more expensive>less sales>Saturn dead
Saturn would've gotten all the PS1 games like FF7, cost $100 less if it was just a simple, easy to develop for 3D console.
Saturn would at least snag half PS1's sales making it Sega's best selling console at ~50M units sold, if it didn't completely bury PS1 sales wise. Sega had everything back in 1994, great 3rd party relations, in house devs, the brand, the cool factor, the tech, the money to make it happen.