Because in november is coming the nes mini, and the version of this game is with mr dream and not tyson, if i submit a run with mr dream is it allowed?

As far as I know, the Mr Dream and Mike Tyson fights are exactly the same. So if you had the original NES hardware, Mike Tyson's Punch-Out and Punch-Out (Mr Dream) would be exactly the same. However if there is some fundamental difference in the way the NES Mini times each fight, then that might lead to an advantage or disadvantage.

Also the PAL and NTSC versions of the game play considerably differently from a speedrunning perspective so if the NES Mini reflects those PAL/NTSC differences, then I could see that being awkward. Since you are from Spain, I suspect a NES Mini would play like the PAL version of Punch-Out

I am just a runner of the game and by no means have any authority on which versions of the game would be accepted as a valid run. I do think there should be a PAL category for the game since there is quite a large difference in the fight times in most fights bewtween PAL and NTSC.

I think, because of the nes mini will be by HDMI, it will be the same pal and ntsc as well as wii u and ps4 and all actual hardware.
But until it releases we don't know, so please any mod tell something.

Mike Tyson's Punch-Out!! and Punch-Out are basically identical outside of the fact that the sprite for the last fighter is switched. I see no reason to not allow a run of regular Punch-Out.

Ok, but my question would be if the nes mini has different timing as the ntsc nes, there will be another leaderboards or what?

What do you mean by different timing?

I mean that nes mini IGT is faster than original for example (idk if it is or not)