Is it permissible now to demand the rights of a father who died in a car accident during work 30 years ago, given that blood money was paid and the salary was discontinued at that time?

If the deceased had a right with the aforementioned entity, it is permissible to claim it. However, if the contract system stipulates the payment of only blood money (Diyyah) without a retirement salary, and this was a condition agreed upon by the workers, then you have no right to a retirement salary as long as the company has paid the blood money.