this game are good for play in 8 gb ram pc?

Yeah, Overwatch is actually very easy to run an 8GB of ram is more than enough. Your CPU and GPU are more commonly bottlenecks when playing this game, but even then, if you even have a low-end gaming computer, you should be able to run the game fine. If you want to optimise you game for the highest possible FPS, I recommend watching this video -- it increased my frames by almost two-fold.
https://www.youtube.com/watch?v=sfUyO6jb6Sk
Hope this helped.