Before filing any PIL Public Interest Litigation, you must make a representation to government. In case you wish to file a PIL exposing some scam, you should first ask for action to CBI or to other appropriate Investigating Agency.
These are normal preconditions.
All PILs basically seek a writ of Mandamous. Such a writ lie when Govt refuses to take action or when it is not taking any action.
This can only happen when Govt refuses such representation or when it does not take action on such representation.
Haresh Raichura 12/8/17