You should probably do this :
echo '<a href="?tutor=link">Tutor</a> | <a href="?institute=link">Institute</a>';
if (isset($_REQUEST['tutor'])) {
$q = "SELECT
'tutor' AS Member_Type,
tutor_code AS Member_Code,
tutor_name AS Member_Name
FROM tutors";
}
elseif (isset($_REQUEST['institute'] {
$q = "SELECT
'institute',
institute_code,
institute_name
FROM institutes";
} else {
$q = "SELECT
'tutor' AS Member_Type,
tutor_code AS Member_Code,
tutor_name AS Member_Name
FROM tutors
UNION
SELECT
'institute',
institute_code,
institute_name
FROM institutes";
}
$r = mysqli_query( $dbc, $q);
echo '<table border="1">
<tr>
<td>Member Type</td>
<td>Member Code</td>
<td>Member Name</td>
</tr>';
while ( $row = mysqli_fetch_array($r, MYSQLI_ASSOC)) {
echo '<tr>
<td>'.$row['Member_Type'].'</td>
<td>'.$row['Member_Code'].'</td>
<td>'.$row['Member_Name'].'</td>
</tr>';
}
echo '</table>';