$_GET['tipos'] will either be - "", "primo", "secondo", or "cambio".
You can see what the submitted data is by using -
echo '<pre>'; print_r($_GET); echo '</pre>';
You would use conditional logic to test what value $_GET[‘tipos’] is to produce each of the <td></td> elements with either the value you want or an empty string.
Php has a ternary operator that can be used to write simple if/else logic in-line.
Based on what I think you are trying to do, I would use -
One would hope that you would examine the code and learn how it works, so that if you want to change the value that gets used you can do so yourself. The documentation for the ternary operator can be found at this link - PHP: Comparison - Manual