What is the religious ruling on grants provided by private or public companies to their employees to perform the Hajj pilgrimage, and are they permissible or forbidden? And what is the ruling on a grant provided by an usurious bank to its employees to perform the Hajj, and is their Hajj valid?

There is nothing to prevent a person from performing Hajj at someone else's expense, whether it is their employer or another entity, provided that the money is from a lawful source. If the money is from a usurious bank, then it is most likely unlawful, because the bank's primary business is usury, and money generated therefrom should not be used for Hajj. Some scholars have stated that whoever performs Hajj with unlawful money, their Hajj is not accepted, even if it fulfills the obligation.