Q: I found a phone iphone 5s 32gb. But mounted icloud,

It doesn't belong to you. Turn it over to the police.

Perhaps you should try posting in your native language. That made very little sense in English.

Regardless of what you do with it, there is no way to bypass the iCloud Activation Lock. It is doing exactly what it was intended to do, making a lost or stolen device useless to anyone other than the original owner.