Got the solution.works fine
$mulcheck=$form['Venue']['facility'];
$mulcheck1=explode(",",$mulcheck);
$data1='';
for($i=0;$i<count($mulcheck1);$i++)>
{
$data1.= $getfacility1[$i]['Facility']['facility'].',';
}
$data = substr(trim($data1), 0, -1);
echo $data;