Type classType = Type.forName('MyBatchClassName');
MyInterFaceName obj = (MyInterFaceName)classType.newInstance();
obj.runBatchConcurrently(); // This is the method which I declared in Interface and implemented in Batch class
system.debug('### obj'+obj); // In debug I am able to see instance of my Batch class
database.executeBatch(obj, 200); // Compile error is coming here