Salesforce connector uses only one record type to synchronize data.

As a result, you cannot use multiple record types with one entity type. However, by adding the logic to separate record types in the mapping, you can use multiple record types as shown below.

{
        "description": "Multiple RecordType per one entity type example",
        "isActive": true,
        "sfdcSource": "configuration/sources/SFDC",
        "sobject": {
            "type": "Account"
        },
        "reltioObjectType": "configuration/entityTypes/Company",
        "to_salesforce": {
            "attributeMapping": [
                {
                    "sfdcAttrName": "recordTypeId",
                    "value": "=source(configuration/entityTypes/Company/attributes/CompanyType).compare(Hospital,0126g0000001111AAA).compare(Laboratory,0126g0000002222AAA).defaultTo(0126g0000001111AAC)"
                }
            ],
        },
        "to_reltio": {
            "attributeMapping": [
                {
                    "uri": "configuration/entityTypes/Company/attributes/CompanyType",
                    "value": "=source(RecordTypeId).compare(0126g0000001111AAA,Hospital).compare(0126g0000002222AAC,Laboratory).defaultTo(University)"
                }
            ]
        }
    }