can duplicate hardwares,can be replaced in dell inspiron laptops?if yes then how to detect it?

You have to identify them from the part number which is stamped or etched on them.
Or use Google Search and the laptop model number to find compatible spares. For example:
Replacement motherboard for Dell Inspiron 15R

That way, the supplier does all the work of making sure you get the right part, you just pay for it.
But check the small print, eg under what circumstances can it be returned or exchanged.