Educational loan

There is a Educational loan in the name of my brother for his btech. He has completed his graduation this year itself. Fees of only IInd year and IIIrd year was paid through the loan. Whereas the fees of Ist yr and IVth year was paid by the father. How to claim deduction of those amount which was not used to pay the fees? He does not have any papers related with the loan, not even passbook of the respective bank account. All the documents are kept by the father. He has denied to pay the loan as well as have denied to give the legal documents. Please guide me what should my brother do now.