Edit: here are some links from Wales:
The official tongue here, and the company, is English. When you're at WORK, speak it.
Your responses seem unusually aggressive.
Edit: canada - the official languages are English and French. You would be unable to do anything if they were all speaking French.
You say there are two groups. One group speaks "Chinese" and the other group speaks "Hindi". So one group doesn't know what the other group is saying. You (rather paranoically) say that they may be talking shit about you. That's true, but the Indians may be talking shit about the Chinese and the Chinese may be talking shit about the Indians.
From your description of events, they clearly already know how to speak English. They choose not to include you in their personal social interactions, in part by not speaking English (but, you know, people can still do that even if they speak your language.)
> The official tongue here, and the company, is English.
Is it? If "here" is the US, it doesn't have an official language. I wouldn't be surprised if the company didn't either -- most don't.
> When you're at WORK, speak it.
If they are violating workplace policies by their non-English interactions, your best recourse is probably to the people responsible for enforcing those policies rather than HN. If they aren't violating any workplace policies, and they speak English to the extent necessary to effectively do their jobs, I'm not sure you have a legitimate grounds for complaint. Certainly, not for entitled demands.