I am able to return only the last data set while making iterated model method calls.

controller

$data['leadd'] = $this->dashboard_model->countt($this->session->userdata('user_id'));

foreach ($data['leadd'] as $q) {
    $date = $q['followup_date'];
    $data['lead'] = $this->dashboard_model->lead_count(
        $this->session->userdata('user_id'),
        $date
    );
}

$data['count'] = count($data['lead']);