My iPhone 6s is locked

Locked in what way? You need to explain.

• Device disabled message or forgot passcode —>If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support
• SIM locked to a carrier: Contact the carrier it is locked to and ask about their unlocking policy—>How to unlock your iPhone for use with a different carrier - Apple Support
• SIM PIN lock—>Contact your carrier for the SIM PUK code
• Apple ID locked—>If your Apple ID is locked or disabled - Apple Support
• Device Activation Locked—>Turn off Activation Lock - Apple Support

Okay, so the iPhone is disabled. Now, you also say that the screen is shattered? There is nothing that you can do to access any data on that device. You can restore the data that was on that phone if you have a backup. If you don't have a recent backup of that phone, then the data is lost. Once the phone is disabled, the data can no longer be accessed. Regular backups must be done before things like this occur.

No, this is a user to user support forum and we are all users here, with the exception of the hosts. If you have an Apple Store nearby you can see about the screen repair, however given the age of that device, it may not be cost effective to do that. Up to you. You can make a Genius Bar appointment and have it examined by Apple and they will give you a quote and explain your options.

You're welcome. Good luck with whatever it is that you are going to try.