It would be racist to assume this happens every time Indian managers make hiring decisions, but I've been at multiple companies that had to put policies in place to distribute hiring decisions amongst committees instead of allowing hiring managers to have the final say specifically because certain managers would only hire from their home regions and caste within that region. It seems like a somewhat widespread problem. I have also seen this happen with Chinese hiring managers, and I'm sure it happens with US-born hiring managers as well, but that's somewhat harder to prove as being in the US a US-based candidate pool is the default.