Can I use duac acne cream on my nose after rhinoplasty?

Yes, but.... Yes, but discuss this first with your dermatologist. You should probably wait until the cast is removed and the preliminary swelling has subsided. While the skin of the nose may be excessively oily immediately after rhinoplasty, it generally returns to its pre-surgical characteristics within a few months.
Yes. Once the nose is past it's preliminary healing phase acne cream is fine to put on the nose. Check with your surgeon for the exact tome frame.
Please spell cream. Not familiar with "duac" cream. Please provide the content information or the correct cream product name.
Why? After rhinoplasty, dressings and a cast/splint may often cause eruptions of oil gland secretions which mimic acne. Gentle cleansing is typically all that is required for treatment.