found the way.
i dont need a separated tab.phtml file.

this portion of codes already put it in product edit tab

    $setup->addAttribute('catalog_product', $attrCode, array(
	'group'     	=> 'Vela Cash On Delivery',
	'input'         => 'boolean',
    'type'          => 'int',
    'label'         => 'Allow Cash On Delivery',
	'backend'       => '',
	'visible'       => true,
	'required'		=> false,
	'user_defined' => false,
	'searchable' => false,
	'filterable' => false,
	//'comparable'	=> 1,
	'visible_on_front' => false,
	'visible_in_advanced_search'  => false,
	'is_html_allowed_on_front' => false,
    'global'        => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL,
    'unique'        => false
));