Answer:
Br, Cl
Explanation:
Several families of halogen oxides are known which give rise to different anions such as the one pictured in the image attached to the question which I can not be able to reproduce here.
This type of anions are commonly formed by chlorine, bromine and iodine. These anions are formed when the octet of the halogen is expanded. This implies that the outermost shell of the halogen now contains more than eight electrons.
