As to how to address it, a first step is the method of reporting. The accusation of discrimination is a serious one, and I'm against hotheaded employees randomly shouting things in slack or emails.

I'd offer an institutional channel to report it to, which will investigate each complaint seriously. The person making the report needs to have a good story, something tangible, some evidence. And I'd take it from there.

If the story checks out and is beyond any doubt, the offender gets disciplined. Preferably a single and last warning. If the story holds no ground at all, the reporter gets a warning for defamation.

Wild generalizations like "all people of caste X discriminate" is a discrimination in itself and not actionable. Keep making generalizations and I'd fire you. This is work, not a postmodernist philosophy class.

Treat it like any form of behavior that creates a hostile work environment and thereby lowers overall workplace productivity. Businesses are incentivized to keep things running in the most productive method possible.

Discrimination costs your business in lowering employee productivity and other affects like possibly losing talent or opportunities. Warning discriminating employees that their behavior could cost them their job or simply firing them depending on the severity of the situation seems like a simple enough solution?