Redirect Page in Subfolder To New Folder - .htaccess

Question

All of these redirects work except the pages located in sub directories for example:
fr/stuff
to
fr/other-stuff
does not work
RewriteEngine On
Options +FollowSymLinks -MultiViews
RewriteEngine On
RewriteBase /
RewriteRule ^/?stuff$ http://example.org/more-stuff [R=301,L]
RewriteRule ^/?fr/stuff$ http://example.org/fr/other-stuff [R=301,L]
RewriteRule ^/?es/notice\.php$ http://example.org/es/ [R=301,L,QSD]
RewriteRule ^/?len.php$ http://example.org/es/ [R=301,L,QSD]
this is the rest of the code
# Use PHP5.4 as default
AddHandler application/x-httpd-php54 .php
RewriteEngine On
Options +FollowSymLinks -MultiViews
RewriteEngine On
RewriteBase /
RewriteCond %{THE_REQUEST} \.htm
RewriteRule ^(.*)\.htm$ /$1 [R=301,L]
RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.htm -f
RewriteRule ^([A-Za-z\-]+)$ $1.htm
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{HTTP_HOST} !^\.localhost$ [NC]
RewriteRule ^(.+[^/])/$ http://%{HTTP_HOST}/$1 [R=301,L]
<FILES .htaccess>
order allow,deny
deny from all
</FILES>

Answer 1

/fr/stuff will redirect correctly to /fr/stuff
but /fr/stuff/ and other content in the directory will not redirect.
To redirect /fr/stuff/ you should do like this
RewriteRule ^/?fr/stuff/?$ http://example.org/fr/other-stuff [R=301,L]
To redirect the subdirectory do like this
RewriteRule ^/?fr/stuff/?(.*)$ http://example.org/fr/other-stuff/$1 [R=301,L]
You should read more about regular expression for details.