What is the ruling on opening a current account in Al Baraka Bank Tunisia—the only Islamic bank in the country—to receive a grant from the state? And should the grant be forgone if that is impermissible?

There is no blame upon you for dealing with the bank to receive the scholarship, even if it is not an Islamic bank, provided that your dealings with the bank are limited to withdrawing the scholarship when it is deposited into the account. However, if you need to keep it and find no other way, you may leave it in the account. The current account is less problematic than other types of accounts.