New map?

[NuclearBomb4]

If I built a map, me and my brother, is there any possibility of it being used?

 

[bluecreeper111]

If it is a good map, it could be accepted. It depends on the quality I think.

 

[Qin Shihuangdi]

If I built a map, me and my brother, is there any possibility of it being used?

Yes, if the head builder believes that the map meets the standards, it could be accepted for the server.
Before submitting your map, you might want to check out these two threads:
https://www.cubecraft.net/threads/the-5-minecraft-building-tips.98001/
https://www.cubecraft.net/threads/player-maps.1064/
When you're ready, please submit the map here: https://www.cubecraft.net/forums/map-submissions.52/