The family may apply simultaneously with the main applicant. But if they didn’t have an opportunity to apply for a visa (and you have already exchanged the visa for a residence permit) or your residence permit was initially obtained in Portugal, then you can request from AIMA a document for family reunification, with which relatives can apply to the consulate for a D6 visa.

The family can also come to Portugal on a tourist visa (or under a visa-free regime) and reunite with you in Portugal under Article 98.2.

NIF and NISS are not mandatory documents for family members. However, if you submit them to AIMA, these numbers will be printed on the backside of the card, which is convenient.