In an unreleased test startpos, I created conditions in which France took over regions as well. (You could make other European factions emergent in India. If Britain succeeds (which is not guaranteed), then this makes Britain into a powerful late-game opponent for the United States (which was one of the aims of the mod). This, at least, means that Britain will compete with other factions for control of India. It happens because, in that startpos, British rebels appear in those regions if there is a rebellion, and I have created conditions in those regions which increase the chances of a rebellion occurring.
However, this does not happen through Britain sending an army by ship. When I use one of the Early American Revolution startpos files (the 18K version), Britain normally takes over between one and three regions in India during the first few years of the campaign.