If you want to show the number of search results found on the search results template, you can find the value in the variable $wp_query->found_posts. Just add

<?php echo '<p>Found ' . $wp_query->found_posts . ' hits.</p>'; ?>

in your search results template. In case that produces no results, try introducing the global $wp_query variable like this:

<?php global $wp_query; echo '<p>Found ' . $wp_query->found_posts . ' hits.</p>'; ?>

The usual method which involves a new WP_Query object does not work with Relevanssi.