Hello Sir,
Please be advised as follows:
If the third party is not ready to sign the compromise agreement, you can continue to file the FIR against the third party and ask the political register the charges.
As a last resort, if you want you can send third party a legal notice, asking him to sign the compromise agreement within a stipulated time else you are entitled to register a case against him under the aforementioned sections.
Please revert in case of query for consultation.
Thank you.