One of the first things I heard when I returned to India for a family celebration was “Ma’am”. I’d forgotten that term. It isn’t that people don’t use it in New Zealand - just not that often.
In India you use it if you’re addressing
• your teachers at school and college
• a client or customer
• your seniors in an organisation or
• a well known personality
In fact you use "sir or ma'am" for anyone you address who you don't know too well, simply as a mark of respect and courtesy.
There are other terms, for example, “ji”, used as a suffix to the person’s name or surname. Rajiv, for example, becomes either “sir” or “Rajivji”. To keep things simple we’ll leave these out for now although I have touched upon “sahib and m’emsahib” in my book, “Never Mind Yaar”.
Of course, there is another school of thought where “ma’am” and “sir” are avoided because they smack, to the user, of servility to the British. But I have noticed that the memory of that period is definitely ebbing in younger Indian minds. They have moved on and are, on the whole, confident and upbeat.
I remember when I lived in India, I used to go ma’aming and “sir-ing” people as a mark of respect too. In New Zealand, I lost the habit as the trend was to address everyone, including one’s boss, client or seniors, even the Prime Minister, by their first names. It took me a while to accept it wasn’t disrespectful, just relaxed. Today, I don’t give it a second thought except when I go back to India and am asked “Can I help you Ma’am”.
Ultimately, however you are addressed, if you are able to judge what the tone or inflection in a voice and the expression on a face convey, you won't go too wrong.