I think if I play earth 18 at deity again I would pick a nation that has no super strong uu at start. Russia could be interesting.
I guess this rules out Inca - or Mali.
Earth 18 is, well, Earth 18. I suppose it is kind of like its own game. When I checked Ice Age Earth, I noticed that it has only 14 players. I wonder if the Earth18 map would be better if we reduced the number of civs from 18 to 14.
I don't know the AI that well. How many cities does it need to present a good civilization and how many does it need to present an overpowered civilization?
After that, I would think of a couple of modifications to the map.
Connect Europe and Africa through Gibraltar. Isolate the Mediterranean Sea. You can still access the ocean through the Mediterranean, but you need to control a tile around Gibraltar.
Connect North and South America with a jungle hill instead of a mountain.
Allow two mountain passes for the Inca.
Maybe I run a test civilization from Easter Island to determine who is still overpowered.
Going back to your question, there is something interesting to be said about India:
The typical Earth strategy is to rush a neighbor, but it does not appear that India has that option.