Please clear my doubt whether 1.Openmrs follows FHIR. 2..Openmrs follows HL7 format.
The openMRS interal storage format is loosely conceptually based on the OBX segment. In that sense, it does not ‘follow’ FHIR or the HL7 format.
On the other hand, openMRS has both HL7 v2 and FHIR interfaces to access the data, though both are a matter of ongoing development. I suggest you take further discussion to https://talk.openmrs.org/