Govt employee joined with False Cast certificate

If so concerned, You may bring matters to the notice of the authorities concerned!

If you have evidence to prove that the officer who was recruited to the government services had done fraud on government for the purpose of this employment you may very well give a complaint to the government department concerned with documentary evidences and keep a record of your complaint, if the government fails to take any action within a reasonable time, you can move high court with a PIL seeking direction to the government for initiating necessary action to inquire and take further legal action as per law. 

how do you  know that certificate was false