This is addressed elsewhere on this thread, but I'll repeat: drivers have no compunction about having multiple apps open at the same time. Nothing ties them to Uber.
If the Taxi app has a significant number of users you might convince driver's to jump through those hoops. But if the Taxi app has no users it's impossible.
This is an easy problem to solve.
Not sure, when they will just have to accept that those drivers are their employees(maybe a lawsuit is needed in India as well).