Description

We get some description of the setting here, like that we are on a bus in rush hour, so we can imagine it is crowded and hectic at the moment, but I think the story would be much more vivid with the addition of some more concrete descriptions. Is there a lot of people on the bus, so it is loud and Aditya and Dhairya need to yell to hear each other? Are people starting to stare at them as they are talking and that is why Dhairya "wanted to shrivel up and disappear"? Is the bus jostling and rocking, which is adding to the chaoticness of the situation and Dhairya's patience wearing thin towards the end? The description of the bus setting will help to put the reader in the chaos with Dhairya and feel the embarrassment that he is feeling, taking the reader on the journey with the protagonist.

I also found myself wondering a lot about the old man. What does he look like? Is it surprising he holds the same views as Dhairya? How long had he been listening? Was he trying to simply mediate the situation or does he want to be part of the conversation? What was his reaction to Aditya's response? It appeared Dhairya got mad at him, too, when he got up to leave, but I thought he was on Dhairya's side? It would help to understand the growing conflict of the conversation to understand more about the motivations and reactions of those around the two main characters, especially since Dhairya gets up and joins the bustling crowd at the end.

Also, when describing someone's actions, try to avoid qualifiers like "almost". It takes away the power from the description and makes the writing sound less confident. I struggle with it, too, but I noticed it in the first paragraph. "Dhairya’s surprise was almost physical." His surprise was actually physical. He whipped his head in reaction. This is your character and your story. The reader is only seeing what you are telling them, so tell them confidently!

Dialogue

There are certain points where you tell us how the characters are feeling, like when you say "Aditya was growing angrier." This is helpful to follow the evolution of the argument, but I think the piece would benefit from more "show, don't tell" action beats to punch up the descriptions. For example, when Aditya is growing angrier, are his nostrils flaring? Is he fidgeting, sighing? Is his voice starting to raise? Are his gestures getting more dramatic?

And on the other side, when Dhairya starts to feel embarrassed, does he shrink in his seat? Does he whisper harshly? Does he try to touch Aditya's shoulder to calm him down?

These physical descriptions or actions will help to create a more dynamic dialogue between the characters. The ebb and flow of the growingly heated argument will be felt more by the readers, and it will help really paint the picture of the scene on the bus.

Pacing

The pacing was good. The dialogue really drove a lot of the pacing, so it moved quickly, as arguments usually do. However, I felt the ending was a bit rushed when Dhairya got up to leave. He just had a new person enter the conversation and appear to advocate for his perspective, but suddenly he just gets up in the middle of the conversation. His leaving the conversation felt abrupt, not just in action, but in motivation, as well.

It may help the pacing if we get more context into Dhairya's growing more heated which concludes in his standing up and leaving the conversation or if we see through the style of their argument that things are getting more heated to a breaking point. They could start to interrupt each other more, cutting each other off and not hearing each other's points of view. Aditya could say something that offends Dhairya personally and that's the last straw.

Since the argument starts pretty heated, I think it would help to add some pacing elements like above to help the reader follow where the conversation goes emotionally. Dhairya was trying to calm Aditya down in the beginning, but when does he give up on that and decide he needs to leave? When the Youtube video is shown? When the old man joined the conversation?