Does Unity use more storage space or Unreal?

in the sense If we are making a same game in both unreal and unity, we have to install certain tools so, for creating the game which engine would use more disc space?

Unreal engine uses more disk space when building games. Not sure about the size difference between engines. I would use Unity if your worried about disk space or performance. Unreal engine has slow build times so your computer would need to be pretty powerful. Also the less memory you have left on your computer the slower your computer is @Nachikethegamedev