It is used to refer to:
* Your father's brother
* Your mother's brother
* An older male friend or acquaintance of your parents
Here are some other words for uncle in Hindi, depending on the specific relationship:
* मामा (mama): Your mother's brother
* फूफा (foopha): Your father's sister's husband
* ताऊ (tau): Your father's brother
The specific term used will depend on the relationship and the region of India.