Is it permissible for an employee to take his full due without the knowledge of the employer who refuses to give him his entitlements except in the old national currency after the collapse of the currency's value?

If your salary and entitlements are stipulated in the contract in US dollars, then you have the right to receive them in US dollars. If the employer does not pay them, you are not permitted to take anything from his money without his permission. Rather, the prescribed course of action is to demand your right from him. If he refuses, then you should refer the matter to the judiciary. If that does not help, and there is no way to reclaim the right except by taking it without the employer's knowledge, then this is permissible according to some scholars.