lenient
i remained calm after my brother hit me
Assuming that you are a female and that your mother actually has a brother, then yes, you are your mother's brother's niece.
If your brother-in-law is the brother of your wife then his mother is your mother-in-law. If your brother-in-law is the husband of your sister, his mother is not related to you but is your sister's mother-in-law.
Your mother's brother's brother-in-law could be your father or unrelated to you
Your mother's brother is your uncle.
Your mother's brother is your uncle. Any child of your mother's brother is your first cousin.
Your sister's mother is also your mother.Your mother's brother is your uncle; and his brother is also your mother's brother, so he is also your uncle.Your uncle's son is your first cousin.
Your mother-in-law.
his brother from another mother his brother from another mother his brother from another mother
A mother's brother is an uncle.
Your mother's brother-in-law is your uncle.
Your mother's brother is your uncle. His brother-in-law could be your father, but could also be another uncle - the husband of one of your mother's sisters - or somoene not related to you at all - the brother of his wife.