Is it worth buying iphone 6 clone?

I want to buy iphone 4s which is original and I want to buy 6s clone. I don't know which one is better

"clone" is not an iphone, that just means garbage parts and design and fake

The iPhone 4s you describe is an old but genuine iPhone running a version of Apple iOS and having access to iCloud, iMessaging and FaceTime.

The "clone" iPhone 6 is not an iPhone of any kind. It's just a lookalike designed just to be good enough to con buyers into handing over their cash. They usually run obsolete custom versions of Android and are made as cheaply as possible from whatever parts are available. There's no after sales support of any kind and the battery is usually very poor quality.

Your choice!

Older original iPhone is better than a newer clone.

I'd recommend the iPhone 4s, it's a true iPhone.