Hi,
You can’t breed birds this way. You should only have one pair of birds per cage, and only one nest box per pair. Each female needs a male. Cockatiels mate for life and both parents help with incubating eggs and feeding the chicks. Your birds are not bonded so they aren’t going to breed. If one male & female do end up bonding, they will start attacking the extra females and kill them if they get close to the nest. Other cockatiels are not welcome in each pair’s breeding territory. Remove the extra females, and only provide one nest box, and see if the male and female bond.
Thank you for asking Lafeber,
Brenda