WordPress Search change

There are plugins that already do what you’re looking for. One that comes to mind is https://wordpress.org/plugins/relevanssi/. Take a look at how they did it.

Whether fuzzy search works also depends heavily on the database system used. As far as I know, database-specific functions are used for this. With MySQL/MariaDB, it is usually MATCH. If this does not work properly with your language, you will probably need to contact your host. You can try it out yourself with direct database access and an example statement with MATCH. See the MySQL manual for more information: https://dev.mysql.com/doc/refman/8.4/en/fulltext-search.html

I wanted to know from someone working at wordpress

This may just be a linguistic refinement, but no one works “at WordPress.” WordPress is open source software that anyone can contribute to. It is available here at wordpress.org, and these forums are for users to exchange ideas. But there is no company or even employees of a company that you could ask about this.

To understand how to influence the search, you would need to familiarize yourself with how it works. Unfortunately, you have not shown us the approach you have taken so far, which does not seem to be working, so it is difficult to tell you exactly what is going wrong.

A key point for intervening in the search would probably be the query hook, see: https://developer.wordpress.org/reference/hooks/query/ – this allows you to influence any database query before it is executed against the database. In your case, you could, for example, first deactivate WordPress’s own search by transferring the s parameter to your own individual setting.

However, you may also need to influence the SQL statement for your project. For this, there is:
https://developer.wordpress.org/reference/hooks/posts_where/
https://developer.wordpress.org/reference/hooks/posts_join/

See also the PHP object that manages the queries: https://github.com/WordPress/wordpress-develop/blob/6.8.2/src/wp-includes/class-wp-query.php – there are a few more hooks there, but I don’t think they are relevant to your case. You would have to use the above-mentioned individual setting to integrate your own database statements, which in turn influence the search, and then reactivate the actual WordPress search for further normal operation. At least, that would be my idea.