As said, there's already two mods that do this.
1) Conquest of Australia, my own mod. It adds a colonial region that encompasses Australia, New Zealand, and eastern New Guinea. It also adds a bunch of Aboriginal tribes, and makes Australia and New Zealand foramble.
2) World Colonisation - simply adds more colonial regions to the game. Doesn't include East Indies though, currently.
I actually think that India and the East Indies aren't particularly well represented by these mechanics though. Hopefully there'll be another expansion dedicated to that. It certainly works with Oceania and (parts of) Africa though.
1) Conquest of Australia, my own mod. It adds a colonial region that encompasses Australia, New Zealand, and eastern New Guinea. It also adds a bunch of Aboriginal tribes, and makes Australia and New Zealand foramble.
2) World Colonisation - simply adds more colonial regions to the game. Doesn't include East Indies though, currently.
I actually think that India and the East Indies aren't particularly well represented by these mechanics though. Hopefully there'll be another expansion dedicated to that. It certainly works with Oceania and (parts of) Africa though.