Not sure if this is question for learning czech or just status, but allow me to mention that in this kind of sentences (sth from/by sth, sth from/by sb),
"od" is used as "from/by" person, company's name...
"z" is used when referring to countries, cities, institutions, nonliving things...
so correct form should be:
Kde jsou balíky z ČR?
Kde jsou balíky od Chunghwa Telekomu?
More info and examples about prepositions can be found at