Yes nose piercings can sometimes smell and it's normal.
When you have a nose piercing and it's starts to smell then it's normal and usually means you need to clean the area around the nose piercing.
The cause of the smelling nose piercing is usually dead skin, sweat, natural skin oils etc all mixed together.
Just be sure to clean the nose piercing often and that should help prevent it from smelling.
Using hydrogen peroxide is a good way to clean and disinfect the nose piercing and prevent any potential infections.
If your nose piercing starts to really smell bad then it could be an infection but just smelling somewhat bad is okay and nothing to worry about.