Can a police officer close a FIR during trial

Hello! As per law, no police station can deny lodging an FIR and they have to do this free of cost. If an FIR is registered, it shall not be cancelled by the police, nor by the Magistrate. Recording of FIR means starting an investigation of a cognizable case which can only be concluded in any of the following ways:

• By refusing investigation under sec.157 (b) CrPC
• By transferring it to a different police station on the question of jurisdiction.
• By submitting a final report after such an investigation or,
• By submitting a charge sheet after an investigation

In addition to the aforementioned circumstances, the government has the power to withdraw the prosecution of a criminal case against the defendant in court. This power is conferred under Section 321 of the Criminal Procedure Code. 

Normally, once the cognizance has been taken, the case proceeds and after a full trial, either result in conviction or acquittal. Before that, discharge of the accused can also be made in some circumstances

• Criminal proceedings barred by limitation:
• As per Section 256 of Code of Criminal Procedure in a summons case.
• Grant of Pardon to an accomplice for becoming witness in accordance with the provisions of Sections 306 and 307 of Crpc
• Withdrawal by complainant (Section 257 CrPc)

For more information, you may read this article- https://www.lawyersclubindia.com/articles/fir-under-crpc-8997.asp 

Hope this helps 

Regards 

You have not posted the complete facts as well the context.

One accused with two sections of 206(¡¡) and 506(b) and case is on presenting evidence before Judicial magistrate