Permalinks are not working

Few day back i shifted my WordPress blog from https://viceroystudios.com/blog to https://viceroystudios.com and changed permalinks by resetting the permalinks itself.
Then I shifted my blog to a new server. But now permalinks are not working. (All pages are opening to a 404 error and that error page is also not the saved 404 page) I have tried changing permalinks to and fro too many times. but haven’t found any results.
It works fine when i am selecting plain permalinks.
Here is my .htaccess file with custom permalinks

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

and with plain permalinks its empty

# BEGIN WordPress
# END WordPress

also i have social links directed to https://viceroystudios.com/blog/yy/mm/dd/post-name how can i redirect them to
https://viceroystudios.com/blog/yy/mm/dd/post-name

[Moderator note: code fixed. Please wrap code in the backtick character or use the code button.]