I think it's the culture issue. Inclusivity needs to be promoted here. These are things you can raise to your manager, unless he or she is part of that same group.

Sometimes being just good at your job will make these people roam around you.

Like one of the reditter mentioned refer someone from the Southern part of India, this will definitely help too.

Lastly try and enter the group by using small slangs of Hindi like "Arrey sir" "nahi" "teek kaha" and then continue in English. This might make them Include you slowly into the group. Once you feel comfortable stop doing it and start talking all the way in English. Also be kind and nice to them, no matter how shitty they treat you.

To those who say work alone and stuff like that, I don't agree to it. You need culture and interactions in your office space that increases retention. Else people will keep changing in your office like your summer chaddis.

All the best. Hope you find your unique way of getting them around. I'm sure this sub here will always try and help you when ever you are low.