You could only put more fish in it once the tank is fixed. And I wouldn't risk it to be honest. If the water leaked out all over the floor it would be a lot of cleanup.
Have you though about purchasing a new 10 gallon? They are like 10-15$ in the store
If you did get the tank fixed properly you might be able to squeeze 4-6 neons in there (I believe) with one Betta.
~Betta Boys ~
Elmo, Felix, Darwin, Kaiju, Rameses, Zeus, Romeo, Bronco, Tyson, Sol-leks, Siren