Try this: You should use array for storage.
$regions = array();
$countR = 1;
foreach ($objR->days as $days) {
if($days->dateMatch == "Yes" && !empty($days->regions)) {
foreach(explode(',', $days->regions) as $r){
$region = str_replace(" / ", ", ", $r)) . "<br />";
array_push($regions,$region);
$countR++;
}
}
}
sort($regions);