கொழுந்தனார் (kozhundhanaar) husband's (usually elder) brother.
You can call your husband's elder brother as "Anna" in Tamil.
The word for brother in Tamil is "சகோதரன்" (sakodharan).
In Tamil, elder sister is called "அக்கா" (Akka).
Your husband's brother's wife in Tamil would be referred to as "மாமிகள்" (mamigal).
"Sister" in Tamil is called "சகோதரி" (Sakothari) for an elder sister and "சிச்டர்" (Sister) for a younger sister.
In Malayalam, elder brother is called "ചേട്ടന്" (chettan).
The word for brother in Tamil is "சகோதரன்" (sakodharan).
Sister-in-Law
You call your husband's senior brother simply a brother in-law. There is no difference whether he is a senior brother or a younger brother he remains your brother in-law.
Your husband's brother's wife in Tamil would be referred to as "மாமிகள்" (mamigal).
Anni
No specific word for Just Brother. Elder brother means Anna. Most elder brother is periya(big) brother. Younger brother means Thambi. Most younger brother is chinna(small) thambi.
what i call my father elder brother's wife
Your brother would call your husbands sister by her first name. Or, "my (sibling's) sister in law.
"Sister" in Tamil is called "சகோதரி" (Sakothari) for an elder sister and "சிச்டர்" (Sister) for a younger sister.
You would call your husband's younger brother a brother-in-law.
I will call her niece.
Your brother's wife is your sister-in-law.