exchange Bahmni healthcare information with Health Information Exchange (HIE) platform that supports HL7 v2.5

One option could be to get this information from Bahmni Atom feed. See this discussion: Introducing Bahmni HL7 LIS Integration

You can also consider using the FHIR Module of OpenMRS. Add that to Bahmni. GitHub - openmrs/openmrs-module-fhir2: This is a module implementing a FHIR interface for OpenMRS