If the complainant files an application under section 482 of the Criminal Procedure Code, the High Court can order the FIR under Section 354 Indian Penal Code, 1860 to be quashed.
The Supreme Court in the case of Anand Kumar Mohatta and Anr v State (Government of NCT of Delhi) , concluded that the court can quash the FIR even if the charge sheet has been filed when exercising the power under section 482 of the Criminal Procedure Code, because the power under section 482 is to prevent abuse of process and miscarriage of justice.
The other option is for the Police Officer in Charge of the Case to report, with the permission of the DCP, that there is insufficient evidence against the accused to charge and prosecute him under section 354 of the Indian Penal Code, and for the Court to close the FIR.
Also, Section 257 in The Code Of Criminal Procedure, 1973 provides that if a complainant convinces the Magistrate that there are sufficient grounds for allowing him to withdraw his complaint against an accused at any time before a final order is issued in any case under this Chapter, the Magistrate may do so and acquit the accused against whom the complaint is withdrawn.
The third option is for the complainant to appear in court and make a statement to withdraw the complaint against the named accused, the complainant can make strong statements in favour of the accused for his acquittal.
It is possible for the complainant to withdraw the complaint based on the abovementioned provisions.
Reference: Section 354 Indian Penal Code, 1860
Section 482 of the Criminal Procedure Code, 1973
Section 257 in The Code Of Criminal Procedure, 1973