I want to download iOS 6.0

- depends on the model of your iPad:
For the iPad first generation (A1219) to update is only possible with connecting the device to iTunes on a computer.
- but this model supports only iOS 5 - NO iOS 6/7/8
--------------------------------------------------------------------
for all other models:
There are two ways to upgrade the iOS version of your iPhone, iPad, or iPod Touch - via connecting the device to iTunes on a computer
- or directly from within the device, but only snce iOS 5, it is possible to upgrade the iOS version without the need to connect the iOS device to a computer (over-the-air update)
just go to: settings - general - software update