To form a buffer solution, specific combinations of acids and bases are required. A buffer typically consists of a weak acid paired with its conjugate base, or a conjugate acid paired with a weak base. Additionally, a strong acid can be combined with a weak base, provided that the weak species is present in a greater concentration. Similarly, a weak acid can be combined with a strong base, again requiring the weak species to be in greater amount.

Examining the provided pairs:

1. **Acetic Acid and Hydrofluoric Acid**: Both are weak acids, but they do not form a buffer since neither is a conjugate of the other.

2. **Nitric Acid and Ammonia**: Nitric acid is a strong acid, and ammonia is a weak base. This combination can form a buffer, assuming ammonia is in greater concentration.

3. **Hydrochloric Acid and Sodium Chloride**: Hydrochloric acid is a strong acid, and sodium chloride is the conjugate base of hydrochloric acid. However, this does not create a buffer because it involves a strong acid and its conjugate base, rather than a weak acid and its conjugate base.

4. **Potassium Hydroxide and Hydrocyanic Acid**: Hydrocyanic acid is a weak acid, and potassium hydroxide is a strong base. This combination can form a buffer, provided that hydrocyanic acid is in greater concentration.

5. **Sodium Bromide and Sodium Hydroxide**: Sodium bromide is a neutral ionic salt and does not contribute to buffer formation. Sodium hydroxide is a strong base, and without a weak acid, this pair cannot form a buffer.

In conclusion, the pairs that could form a buffer solution are **Nitric Acid and Ammonia** and **Potassium Hydroxide and Hydrocyanic Acid**.