CHECK YOUR ICLOUD STATUS
Here you can check if your device is locked by iCloud or Not.
Find My iPhone includes a feature called Activation Lock that is designed to prevent anyone else from using your iPhone, iPad, or iPod touch if it’s ever lost or stolen. Activation Lock is enabled automatically when you turn on Find My iPhone on a device using iOS 7 or later. You must use your IMEI type into your iPhone +#06# to find IMEI. In an alternative to find your iDevice IMEI, you must download ibackupbot for mac or windows.
Connect your iDevice to a computer after installing the software. the software will show your device IMEI, UDID SERIAL Number. Also using this software you can check if your device is locked to icloud. With your IPHONE imei is important to check if the device is on any blacklist database world wide. Before you buy any device please be sure if its not blacklisted and icloud is turned off .