What is the ruling on the money that reached my account from a relief organization after I exaggerated the number of needy individuals in my family, and is this money considered unlawful, and how should I dispose of it?

If organizations send money based on a specific number of dependents, and the number is incorrect, then it is not permissible to take all or part of the money if the condition was clear. You must repent and seek forgiveness. If you cannot inform the organizations of the truth, take a quarter of the amount that corresponds to the number you actually support, and give the rest in charity to the poor and needy. An exception to this is if you are in dire need of the money, in which case it is permissible for you to take what meets your needs, because organizations aim to help those in most need.