Merhaba @Centox;,
Aşağıdaki kuralları dener misin?
(siteadi.com yazan adresleri güncellemeyi unutmayın)

RewriteEngine On

RewriteBase /

RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
Options +FollowSymLinks
RewriteCond %{HTTP_HOST} ^siteadi.com [NC]
RewriteCond %{REQUEST_URI} !^/[0-9]+..+.cpaneldcv$
RewriteRule ^(.*)$ https://www.siteadi.com/$1 [L,R=301]

RewriteRule ^basvurular basvurular.html [L,QSA]
RewriteRule ^iletisim iletisim.html [L,QSA]
RewriteRule ^nedir nedir.html [L,QSA]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !.*.(ico|gif|jpg|jpeg|png|js|css)
RewriteRule ^([^?]*) index.php?_route_=$1 [L,QSA]