So let's take it back to the OPs premise: raksashas exist in Eberron. Raksashas are Indian-coded due to their rw origin. There is no India analog in Eberron. How do you fix this?
One of the suggestions is that if the setting lacks a stand in for a particular culture, the monsters from that culture shouldn't be included. I've seen similar arguments about things like monks or samurai as well. Eberron, lacking analogs for real world cultures, shouldn't use those elements. I suggest if that's going to be the case, then break it up by culture so that it becomes part of the package deal. You want Chinese elements in your game? Get the China supplement. It's been researched and written by experts in Chinese culture and is faithful to the source material and respectful to the culture.
And my suggestion is, if that particular aspect bothers you, do some research on Indian and Chinese cultures, and find ways to make those elements make sense, or find ways to represent those cultures more effectively in-setting.
This doesn't have to be hard. I don't know Eberron very well, but from what little I already knew or can find:
- The Dhakaani Empire could easily have had significant influences from various historical Indian Subcontinent cultures, such as the Mughal Empire, or the Chola Empire, which spawned from a dynasty that--no joke--lasted over a thousand years. That would fit in extremely well with the Dhakaani, who ruled what is now called Khorvaire for several thousand years. The Rakshasa could have adapted to that culture as part of their efforts to awaken their overlords, and to them, the three or four centuries that the new nations of Khorvaire have been around is nothing.
- The dragonborn of Q'barra and Argonessen prove it is possible to expand the world with new elements by finding appropriate places for them. Keith Baker, the creator of Eberron, even seems to have been pretty enthusiastic about incorporating Dragonborn into the setting--to the point that, if they were building Eberron today, he'd consider making them a dragonmarked race. Perhaps they are the ones who have the samurai and other such things, traditions they had for thousands of years before the Dhakaani drove the early dragonborn out of Khorvaire. They continue to uphold the true source of the traditions behind said fighting styles and armor types.
Far from perfect, to be sure, and you'd want to do some work to be sure things fit together properly. But surely better than trying to just rip the Rakshasa out entirely, and thus having to rewrite major parts of the setting? Good-faith efforts have
got to be better than flippantly ignoring the issue
and better than cutting everything up into perfectly segregated, non-interacting pieces, "how
dare you try to run an Arabian Nights setting without the
Official Arabian Nights Book (Coming 202X!)"
It just seems both reductive and counter-productive to take "this is kinda iffy, lifting aesthetics and behaviors from real or historical cultures without any real basis or merit in it" and thus conclude "
burn it all down, slice everything up into its own neat little totally separated non-interacting boxes."