Setting a field collection default value for a field using form
This is how I resolved this.

$language = $form['field_fielc_collection_group']["#language"];
                    $iterates = $form['field_fielc_collection_group'][$language];

                foreach($iterates as $multi__key =&gt; $iterate){
                            if (is_integer($multi__key)){
                                        if(is_array($iterate)){
                                            $delt = $form['field_fielc_collection_group'][$language][$multi__key]["#delta"];
$form["field_fielc_collection_group"][$language][$multi__key]["field_to_set_default"][$language]["#default_value"][$delt] = 'default_value' ;
                                        }
                            }
                }