Uphill Driving, Highway.. I have used Power Mode, since It gives power like 1800cc and is needed for overtaking at Highway and High Torque for Uphill
For City driving drive at both Normal or Eco Mode... although i switch to eco mode in traffic jam.. You can also drive Power mode in city, it all depends on your driving style, if your habit is heavy foot then Power Mode all the time...
Don't switch to EV mode, because EV mode will drain battery fast and can reduce the life of battery!