Common oxidation states of mercury are 1 and 2. In the 1 oxidation state, mercury forms a diatomic cation. In the 2 oxidation state, mercury is a typical monatomic cation.

The question is asking to calculate and give the formulas for the mercury bromide, base on my research, the answer would be HgBr, I hope you are satisfied with my answer and feel free to ask for more if you have questions and further clarifications