What is the Sharia ruling regarding what a person owns who bought a farm with an interest-based loan, then established projects on it with the help of his family and friends, and now wishes to repent while still paying off the loan? Should he sell the farm and the projects on it, or what should he do to rid himself of this money?

A loan with interest is usury itself and is among the gravest of sins. The borrower must offer sincere repentance, express remorse, and seek forgiveness. They must repay the principal amount to the bank if possible. If the bank compels them to pay the interest, then the burden of that sin falls upon the bank. They are not required to sell the farm, house, or projects established with the loan after repentance, for "the one who repents from sin is like one who has no sin."