Permissibility of ones brother-in-law acting as a witness for Nikaah

Aslm Mufti Saheb. I would like to know if it is permissible for one’s brother-in-law (sister’s husband) to be a witness for the nikaah. The girl getting married has a father and brother and no other mahrams to represent her as the third witness. Please advise. Jazakallah.