outside crack and screen are visibale

@nagarajrathod even with just that outside crack, you still need to replace the complete assembly. iFixit doesn't yet have a guide for this. Use the guide from here

The display is readily available at many online stores. Select a vendor that appeals to you.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.