If your brother-in-law is your wife's brother, his son is your nephew and you are his uncle or aunt.
If your brother-in-law is sister's husband and his son is also her son, he is your nephew and you are his uncle or aunt. If the brother-in-law's son is from a marriage to a woman other than your sister, and your sister has not adopted him, he is not related to you. However, you may choose to treat him as your nephew, especially if he came into your life as a young child and considers your sister to be his mother.
If your brother-in-law is the brother of your spouse, his son is your spouse's nephew and therefore your nephew.
If your brother-in-law is the husband of your sister, and his son is your sister's son, the son is your nephew. If his son is not your sister's son (being from a previous marriage) the son is not related to you unless your sister adopts him. However, there is nothing preventing you from calling him your nephew and treating him as such, if you care to do so.
You brother-in-law's sister's son may be your son, your nephew, or may not be related to you at all.
I'd use her name. If the Brother in law is married to your sister, she would be your nephew's wife. And you are not related by blood.
Your brother-in-law's nephew may be your son, may be your nephew, or may not be related to you at all.
errrr, no maybe nephew
what i call my father elder brother's wife
Your wife's brother is your brother-in-law.
Your sister in law is your husband's sister or your brother's wife.
Your Brother in law's wife
Your wife's brother would be called "brother-in-law".
younger brother's wife -- maradalu elder brother's wife ---vadina
The brother of your wife's cousin is also her cousin. You can call either of them "my wife's cousin." You are not related to them.
what i call my father elder brother's wife
Your wife's brother would be called "brother-in-law".
what i call my father elder brother's wife
Brother-in-law
Your brother's wife is your sister-in-law.