Any tips for plating Indian food?

Thanks, everyone! I think I'll take a combination of approaches that you all have mentioned - the ramekins are a great idea!

You could plate all the major dishes (don't worry too much about things running together at their boundaries) and have sauces and chutneys in small serving dishes, as well as any bread, at the table. Assuming you're serving rice, it's easy to mold it in a ramekin, bowl, or takeout container and invert that onto the plate to give it a little visual appeal.
I'd probably instead lay out the dishes as a buffet on another table or counter, or pass them around the table and bring a side table or two nearby to place the dishes on after everyone has served themselves.

Depending on what your making, try small ramekins or bowls for the wetter ingredients. You could put one in the middle of the plate surrounded but rice or drier ingredients or keep it to the side off the plate. I have done this before with salsa and bagna cauda. Let us know what you decide to do.

I'd say go with the thali plates or a big platter with little steel katories (bowls). The banana leaf plating is for advanced palates! :-)

If you're going to do this often, or have use for them around the house, consider buying some thali dishes...used in Indian restaurants in the Western world (maybe elsewhere, but I don't know for sure). Have space for the main (dryish) dishes and either compartments (like an old Swanson dinner tray) or small bowls for every person for the wet sauces and garnishes. Here are images of many:
https://www.google.ca/search?q=thali+dishes+stainless+steel&espv=2&biw=1517&bih=735&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwi14t6_2NzRAhXH3SYKHVANAKcQsAQIMA
If you have no need or access to these plates, consider investing in a set of ramekins (open casserole, ceramic, usually about 4 oz but available smaller & larger).
These are well worth having as they have multiple uses, e.g., bake souffles or individual molten chocolate cake, use as mise en place, butter server.
For the Indian dinner, serve the sauces in these, with small spoons, in the middle of the table, for people to take as much or little as they wish.
Also, you may consider serving the main dish on salad plates (usually sized up to 9 in diameter, smaller than dinner plates, usually 10-12 in diameter).
https://www.google.ca/search?q=thali+dishes+stainless+steel&espv=2&biw=1517&bih=735&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwi14t6_2NzRAhXH3SYKHVANAKcQsAQIMA#tbm=isch&q=ramekin+dishes
And I hope that gives you enough space for the dinners, garnishes & some drinks.