PKS-
There's an interesting comment by Sean Connery on this:
https://www.youtube.com/watch?v=oo0d1zTAFKA
One of the reasons it seems to happen is women are typically better communicators than men are, and will sometimes verbally box men into corners that the men know they shouldn't be in. Because the man is unable to express why the woman is wrong, he becomes increasingly angered at her pestering/obstinacy and eventually resorts to smacking her (the reverse occurs when you have women hitting men much of the time too - the guy's being a dick and the woman is at a loss to express herself or feels like nothing she says is getting through to him).
I tend to date pretty rational, educated women, I'm a pretty darn good communicator, and I've adopted women's argumentation methods well enough that at this point I can
beat them at their own game, so I've never had nor desired to raise a hand to a woman. If I ever had a girl absolutely losing her shit and it was necessary for her to calm down at once (say, we were in some kind of dangerous situation), though, and the situation demanded it, I would not hesitate. However, it's been my experience that when a woman's absolutely losing her shit and not listening, all I have to do is get really angry and tell her to calm the fuck down right now, and seeing a normally-always calm guy switch into borderline rage mode is enough to make them suddenly want to have a reasonable discussion. I can't say I've ever been in a situation where slapping a woman was warranted. Most of the times men do this seem to be when the man himself feels too personally embattled and simply lashes out to stop the ego beating a woman is giving him.
One big mistake a lot of men make is once the woman has calmed down, they feel the need to reassert dominance, so start telling her she was wrong (instead of listening to her side of the argument), which prompts her right back into the attack again. It seems like this is where a lot of the hitting that does occur occurs. The woman prompts it by cornering the man, but the man prompts the cornering by egging her on instead of talking rationally when she dials it down and is open to this. The right way to proceed if she's just calmed down from flipping out is to say, "All right. Now can you rationally explain your position to me? If so, I will listen. If not, I don't want to hear it."
I suspect for many men, who suck at communication compared to women, this isn't as much of an option: they aren't going to bother to learn communication as well as women (who have a larger part of their brain devoted to it, on average), but they're still going to know when a woman is using her verbal prowess in an abusive, slanderous, and manipulative way (typically because she's angry at you for something, or sexually frustrated). So they respond almost unconsciously by just lashing out when they reach a certain threshold of being cornered and embattled too far.
You're in India, and it's been my experience Indian men from India in general are not the best communicators and are extremely reliant upon hierarchy. e.g., an American style of consensus-based leadership is confusing and bizarre to Indian employees, who are used to top-down leadership. Indian bosses don't take nearly as well to push back or criticism from inferiors. This seems to translate to relationships as well. Indian men are less inclined to want to deal with an uppity woman because they expect her to respect the hierarchy. A slap or a beating is one way to enforce that hierarchy, when words fail. I imagine that's why they're telling you sometimes this is needed.
Chase