How to file a PIL against government organisation

How to file a PIL in high Court against corruption in a govt org. we had already informed about this matter to the highest authorities (IAS and RAS ) in that organisation. almost 1 year has been passed. we had given many certified documented and audio proofs which clearly reveals the corruption but still every time they disposed the complaint by giving reason that matter not found correct . govt runs on tax paid by people's and hence making finencial loss to gov is equivalent to finencial loss of public and cheating public. This matter was also published in state's leading newspaper on front