Is it permissible to take and benefit from the money sent to a contestant who did not succeed in the competition to obtain an entry visa, which came from the contribution of a group of banks?

It is not permissible to participate in competitions that require the payment of fees or material costs, and the money obtained from them is considered unlawful. However, if participation is free and travel to the country is permissible (such as for learning, Da'wah, or treatment in the lands of disbelievers), then participation is lawful, and the money earned from it is permissible. The source of the money, whether from banks or elsewhere, does not affect its permissibility, following the example of the Prophet (peace be upon him) accepting gifts from disbelievers.