Redmi note 3 is the best mobile under 12, 000. I have a rermi note 3 .its support upto 64 gb as I used .thats in multicore perfomance in single core snapdragonn820 is still the king.
Redmi series has been wildly popular over the past few years and for good reason.the low prices and good features have really set these models apart .the lock screen gets a feature called wallpaper .xiaomi has incorporated a one- hand mode which you can enter or exit by simple swiping right from the capacitive home button.