I've heard of this claim so often that I assume it to be true, though personally I've only had the fortune to work in better environments where my Indian colleagues aren't nepotistic. I suspect this might be related to the hiring bar: if a company only hires the top talent perhaps this would not be an issue.
Unfortunately I think it depends on the number and position of Indian folks.
Small numbers where you deal with people individually, I've not seen issues and it's nice to work with Indian devs.
In larger numbers or when in charge of hiring, there seems to be a prevalent issue of Indian cultural norms and favors kicking in and it can happen fast.
