Naming conventions
India has many different cultural groupings, hence different regions have different name traditions. Ask if you're unsure. This will probably offend people the least. Generally speaking, it is safe to address an older as "sir" or "Ma'am." Indians typically use their "given name" at work or while speaking to individuals they don't know well.
In India, a lot of people also have nicknames for their family and close friends called "pet names." Even if they are not related, elder women are frequently addressed as "auntie." Younger men are commonly referred to as "little brothers." Family names or surnames frequently indicate a person's caste or region of origin; they may also carry a suffix that indicates the nature of an ancestor's trade.
Indians may also go by another name for their religion. Muslims frequently lack surnames. Instead, men use the connector "bin" to combine their own name with the name of their father. Sikhs all use the name Singh, for instance, Abdullah bin Ahmed is Abdullah the son of Ahmad. It is either used as a connector name to the surname or as an adopted surname.