Invoking section 258 og crpc in crpc-125 case is valid?

Read the wordings of the section it is applicable for OTHER THAN COMPLAINTS, so far private cases this section can not be applied.

258. Power to stop proceedings in certain cases.

In any, summons that case instituted otherwise than upon complaint, a Magistrate of the first class or, with the previous sanction of the Chief Judicial Magistrate, any other Judicial Magistrate, may, for reasons to be recorded by him, stop the proceedings at any stage without pronouncing any judgment and where such stoppage of proceedings is made after the evidence of the principal witnesses has been recorded, pronounce a judgment of acquittal, and in any other case release, the accused, and such release shall have the effect of discharge

Means, the cases that are not filed by the Police..... means private cases .... correct me if I am wrong in reading the section...

Complaints means private cases.

All other cases are police cases.

So this section is not applicable for private cases.