Currently, family reunification in the Netherlands is only possible for members of the core family unit. The core family unit are the partners/spouses and children under 18. The (grand)parents of adults are not part of the core family unit. It is however still possible to bring your parent to the Netherlands in some cases.
They can only come if ‘more than normal emotional ties involving additional elements of dependency’ (in the sense of article 8 of the ECHR) exist between the (grand)parents and their adult child.
‘Merely’ getting old and needing support unfortunately does not constitute more than normal emotional ties, as this is not considered abnormal. In practice it is only possible to meet this condition if there is (extreme) dependency of the elderly parent on his adult child, e.g., because of severe health problems.
To prove this, the parent and adult child would have to provide evidence of the parent’s medical conditions for which he requires help from others. Then they would have to provide evidence that the parent is solely dependent on the adult child in the Netherlands for his care and that there is no possibility for the parent to receive such care by hiring professional help in the home country or get help from other family members. The IND is extremely strict and harsh in these types of applications and only in exceptional circumstances, these permits are granted.
If the child/the children in the Netherlands are not permanent residents or Dutch citizens, it is virtually impossible to bring your parent/parents from outside the EU to the Netherlands.
Nb. If family members have the nationality of one of the other member states of the EU, or it concerns Dutch citizens who have recently lived in another member state of the EU, other rules (may) apply.