@Queriest,
The nature of the case decides if the case is vs State or vs an Individual. Complaint which are civil in nature always come under private Complaints(Exception if done against a State).e.g. Mr. X vs. Mrs. Y and so on.
On the other hand if Complaint is of Criminal nature, it' always against the State.e.g. State Vs. Kharak Singh and so on.
It's strictly not an excercizable option for an individual to decide to make the case private or against the state.
An advice for you and like you-
Advices are free gifts here and one doesn't know his/her boundary in such context. People who Offer such advices,Who even don't know the basics of Law and pretend to know the nuts and bolts of law,always speaks non-sense and yet they are not ashamed of their act by repeating such advances. Therefore,Beware of such people and always try to find the truth from reliable sources.
In this very query and all other prospective query in any matters including law matters,you can find the truth by searching google and finding authentic and reputable Source or reading textbook of law.
Thanks,
Regards,