how to unlock my iphone 5c using itunes

Unlock?

Carrier unlock?

Passcode unlock?

Something else?

Please explain

"Unlock"?

Are you talking about being locked to a carrier? Contact the carrier to unlock. They are the only ones who can.

Are you talking about passcode unlock? Then see http://support.apple.com/kb/HT1212

Are you talking about Activation Lock? Then you need the original Apple ID and passcode the iPhone was locked to.

please can u unlock my passcode by connecting to itunes on an iphone5c