Hi Aruna,
You should not be trying to breed your finches when you have several pairs in the same cage. For breeding, you need to have one pair per cage. You can keep all of them together, but you should take away the nests. You have created a hostile environment by only have 2 nests, with 3 pairs of finches. Finches are very territorial when they are breeding, which is why they should never be bred in groups. Each pair needs a territory, and other birds are seen as rivals. If a rival bird gets too close to a pair’s nest, it will be attacked or even killed. It sounds like this poor male has been picked on and bullied. He’s probably staying in the nest to try to survive. You need to either take away the nests, or split the birds up into 3 cages. If that egg hatches, at some point the other birds are likely to kill the chick when the male leaves the nest. Even if you did not intend for the pots to be nests, anytime you have a group of birds, you should take away anything they try to use for a nest. If these were for food, then replace them with small cups they can’t sit inside of. But if you leave things as they are, you will end up with more of them fighting, and adults or chicks being killed.
Thank you for asking Lafeber,
Brenda