I mean if my team win and i had 0/0/0 at heroes at 0/0/0 at mobs and 0 towers down (this is an example:)) i get the same points as if i made 8/3/6 at heroes and 45/10/12 at mobs??
Yes, you get the same points regardless of your score.
Because PSR gain/loss is counted before the game even begun, so your in-game score doesnt affect you gain/loss PSR.
I hope you understood me