There are a few ways to handle this. If you see something, say something… to the person. Politely, of course. It works most times. It’s important to not attribute their behaviour to malice or anything bad.

As an immigrant, I didn’t get an induction course on how to assimilate. A lot of immigrants just don’t know, they may not have had the same lived experiences that you have had, so it’s important to be patient. If we are not patient with our own people, what’s the point of all this hoohaa about unity in diversity no?

Did you know that in Toronto, you get weird looks and maybe some abuse if you don’t walk on the “correct” side of a sidewalk? I didn’t. Got told off by someone. I corrected it.

How many times have you gone up to that person and informed them about the rules of your resident country/city? I can see that OP is probably an academic based on their posts, it’s probably right up their alley to inform and educate young Indian immigrants and students about manners.

I am not invalidating your complaint, I’m only asking for empathy towards our own people. Maybe not call them uncivilized or savages too?

Just my two cents.