to which HR said under Polish law that can not be disclosed.
Ridiculous. Just ask them which law they are talking about... and also ask them to put themselves into your
Would they travel to a job interview without knowing what the salary proposed is? Lol
Logically if you answered 6 k and they replied with this fallacious pretext of not beeing able to disclose a salary under Polish law, it means that they are offering peanuts and ashamed of it...