Your mother-in-law's brother would be the uncle of your spouse. The two of you do not share a common ancestor.
No relation
Brother in law
brother
Brother-in-law
Your brother or brother in law
your brother's daughter is you niece
your brother
Your niece's brother is your nephew.
He's your brother-in-law.
No. The sister is a relation, and her husband is an in-law. The husband's brother is no biological relation either. Therefore, the great granddaughter of the husband's brother is not a relation.
They are brothers in law
brother's daughter relation