The best radio taxi service according to me is the Ola Cabs mobile app based service! I use the service in Mumbai and Delhi and both the cities have given me great experience.
The drivers are safe, cars are well maintained and the time management is perfect!The App is free to download and is easy to use!
The customer support is also very prompt.The billing is all transparent and with use of GPS system, the routes are always perfect!
I recommend everyone use this and also get a discount on the first booking with the code provided by the App!