Naturally, an All Indian NFL team would be made up of players with a direct line of descent from the country of India (of which, I don't think there are enough to even form an offensive line at present - even if you exclude the centre and both guards). Non-withstanding that, I'm only assuming you are referring to what is commonly referred to now as First Nation people - they used to be called Indians, or Injuns (whenever John Wayne shot them off their horses) but in some places they are still referred to as Redskins, which Australians tend to give to little tackers as a treat to eat. Not that Australians are cannibals (or anything - despite relentlessly taunting one of our greatest Aboriginal mates when he plays football), but I think most Americans would be too conceptually challenged to watch a team made up of a bunch of chewy candy sticks trying to play football. Indeed, most Americans would also avoid (at all costs) buying a mass-produced cheddar cheese made by Kraft simply because of its colloquial product name. It's probably why JL Kraft (an American global conglomerate) wouldn't even try selling it anywhere else in the world but here.
But that's just those weird Americans - here we like to eat Redskins, carve a good chunk off a block of Coon and boo one of our greatest footballers for being a proud Aboriginal man. Funny world.