@ishfaqbhat If your display assembly has failed it's time to replace it. Since iFixit does not yet have a guide for this, use something like [link|https://www.youtube.com/watch?v=16FKqQO1Uk0|this video] or even the guide [link|https://www.nadiemellamagallina.com/en/manuales/smartphones-1/vivo-926/vivo-y20s-1291/|from here] It's for a Y20S but it's identical to your phone. It was written in Spanish so you may need a browser that can translate it for 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 a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
Repair is War on Entropy!