Try with this rules in your .htaccess file:

# rule for forcing www on main domain
RewriteCond %{HTTP_HOST} ^mydomain\.com$ [NC]
RewriteRule ^ https://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

# rule for removing www on sub domains
RewriteCond %{HTTP_HOST} ^www\.([^.]+\.mydomain\.com)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [R=301,L]

It seems www. version is not secured by your installed SSL. It is trying to connect over HTTPS – but your SSL is not covering www. hostname.

You can see non-www SSL scan here: https://www.ssllabs.com/ssltest/analyze.html?d=hindi.aadhaarcard.net.in&latest
and the www SSL scan here: https://www.ssllabs.com/ssltest/analyze.html?d=www.hindi.aadhaarcard.net.in&latest

Hope this helps you figure it out!

Cheers,

Liam

Contact your hosting provider / SSL provider.

They should be able to fix it for you!

Cheers,

Liam