What is the ruling on health insurance that stipulates paying premiums to a society which in turn pays them to an insurance company, with a cap on treatment, and the other insurance that is deducted from the monthly salary for treatment within certain limits, knowing that the second insurance is not obligatory?

The insurance mentioned in the question is impermissible due to its包含 uncertainty (gharar) and gambling (qimar). The fact that the financial ceiling paid by the insurance company is fixed does not affect the ruling. Similarly, the existence of an intermediary, which is the association organizing it, does not affect the ruling, nor does requiring a specific number of participants. Deducting from one's salary for this purpose is forbidden, and cooperative insurance is recommended.