I have written below code in htaccess
RewriteRule ^([a-zA-Z_-]+).php$ http://www.domain.com/myfile.php?page=inc-$1.php [NC]
I don\'t want the index.php file
I think this is what you're asking:
"I want to allow the index.php file to be served normally, but all other requests follow this rewrite..."
To keep the index file from being redirected, you need a RewriteCond before the rule:
RewriteCond $1 !index\.php
RewriteRule ^([a-zA-Z_-]+).php$ http://www.domain.com/myfile.php?page=inc-$1.php [NC]