Cheating case by a bank

Sir, We are in a really bad situation. My father is above 70 and has had some issues focusing on things. He runs a small company that has been making some losses recently. A company called Apurva approached him and they told him that they need a collateral for their company loan for 5 months after which they would return the collateral. My father was given some money (less than 5% of the home value) for this arrangement. The Bank manager at one of the biggest banks in the country also colluded with them and convinced my father that the company is legit and they do this from time to time. My father agreed into a contract. The issue aroused when my father after the term of the contract asked back for the property. The company started making threating calls to my father, told him to forget about the property, and threatened that he should give the house to them. When my father approached the bank for relief, he found that the bank manager has been promoted and transferred to another location. My father after getting multiple threats went to the police and lodged a FIR. Now, my father is fighting a court case (where he has put both the bank the Apurva as parties that cheated him) to save the house, after the bank issued eviction notice. The other company (Apurva) is untraceable. My mother and I were told about this only recently and are shocked. Please let us know what our options are. The court has given a date later this month. Would really appreciate any help. Thanks.