Cheque deposited without consent

Myself, my mother and my elder sister are owning an agricultural land acquired by my late father. I am currently living in Mumbai. The property is in Tamilnadu. My sister took a loan from some private party keeping this land documents without the consent of me. My mother who is 78 years old is not knowing anything about property, bank, cheques etc. She was forced to accept for this loan matter. My mother's three blank cheques my sister two with her signature alone and had given to the concerned party as an assurance document. The interest was not paid by my sister though my mother was sending the amount(through me) to my sister every month. The party called my mother saying that so far no interest was paid and my sister had told him that my mother is not sending any money. I responded to him saying that I have the evidence of the bank transactions for sending the amount to my sister. I also told him not to deposit those cheques without asking us. But today my mother has received the bank sms stating Rs. 60000 has been debited to somebody's account(the name is not that of the lender). Checked the transactions. The amount has been debited. Can we sue this lender for not consulting before depositing? Does it comes under material alteration since the amount filled and the name of the payee was not consulted with my mother before depostiing?