Is it permissible to take a loan from banks that allow loans or financing for marriage, knowing that the salary is not sufficient for the expenses of marriage and the bank considers it permissible?

The questioner did not mention the method of granting the loan or the financing transaction for us to rule on it. If the bank is an Islamic bank and has a reliable Sharia supervisory board, then there is no harm in dealing with it. It is preferable to inquire from the bank's Sharia board, and if they issue a fatwa—and they are reliable—then there is no harm in following their opinion.