how to read and validate json file using testcomplete

Use JSON, here's an example,

function Test1()
{
    let text = '{ "employees" : [' +
        '{ "firstName":"John" , "lastName":"Doe" },' +
        '{ "firstName":"Anna" , "lastName":"Smith" },' +
        '{ "firstName":"Peter" , "lastName":"Jones" } ]}';
    
    var obj = JSON.parse(text);
    for (var i = 0; i < obj.employees.length; i++) {
        Log.Message(obj.employees[i].firstName);
    }
}

You can use aqFile.Compare Method to compare both JSON files