when i make a cname verification google says that it cannot able connect to the server
if your domain is new (day or two)
You need to have patience for DNS propagation cca. 2 days
after that even HTML file upload verification works
https://infinityfree.net/support/how-to-verify-your-website-in-google-webmasters/
I doubt Google would say “cannot able connect to the server”, because Google is an American company and that sentence is not valid English.
What is the full error message presented by Google (not just your interpretation)?