Site has been down after changing name servers

My site has been down since i changed the original name servers to the new cloud-flare name servers.
I believe its error 506 with “Variant Also Negotiates”.

How can i resolve that?

Hi @fresherjobsuganda, the error message reported definitively does not from Cloudflare. From search on Google, some 506 error code detaul, https://httpstatuses.com/506

Your origin server logs should show traces of this error to help troubleshoot.

Hello Cloonan,
Thanks for reply.
Unfortunately, the error changed to something below;
Error 1000 DNS points to prohibited IP

May you have an idea regarding how to resolve the same?

You have probably entered a cloudflare IP address as the value of your A record called the same thing as your domain. That IP address should be the IP of your origin server and the A record should be named @