We have a 93 year old individual who wants to co-sign an unsecured loan for her granddaughter for college tuition. The 93 year old co-signer receives social security and the income is sufficient to service the loan payment and the credit history of the individual is excellent. Is they anyway we can deny this loan without violating Reg. B?

NO!!! If the person is capable of repayment, then you do not have a proper reason to deny the loan.