The search engine that is integrated with Drupal is not working for me in searching contents

Could you expand on this a little?

Are you getting no results? If so, you may need to adjust the indexing settings and run cron.php. (To run cron manually, add "/cron.php" to the URL of your website.) In order for your site to be indexed automatically, you will need to arrange for cron.php to be run at regular intervals. You can do that either by setting up a cron job at your hosting provider, or by installing the Poor Man's Cron module.

Are you getting results that aren't very relevant? You can adjust the weighting of search terms in the Search configuration, or try installing the Porter-Stemmer module to add the ability to find stems (like finding "blog" when searching for "blogger"). (There are also Spanish and German "stemmer" modules.) (Disclosure: I haven't used the "stemmer" modules, so I'm just making a suggestion here.)