How to so index of single product? I have tried below code but it's not working.
Mage::getSingleton('index/indexer')->processEntityAction( $product, Mage_Catalog_Model_Product::ENTITY, Mage_Index_Model_Event::TYPE_SAVE )
is there any other solution?
You can do product indexing by their attribute like this:
$indexer = Mage::getSingleton('index/indexer')->processEntityAction($_product, 'catalog_url', Mage_Index_Model_Event::TYPE_SAVE);
Hope, it works for you.