For windows user, make sure to closely look at this section.
RewriteRule ^properties$ /property_available.php/$1 [NC,QSA]
As said in Apache documentation :
The mod_rewrite module uses a rule-based rewriting engine, based on a PCRE regular-expression parser, to rewrite requested URLs on the fly.
So ^properties$
means Apache will only look for URL that has exact match with properties
.
You might want to try this code.
RewriteRule properties /property_available.php/$1 [NC,QSA]
So Apache will see the URL that has properties
and rewrite it to /property_available.php/