Defaults of payment after last extension order from high court

Hi, my father's case is going on in high court. He had to pay 23 lakhs to the complainant, of which only 9.5 lakhs are remaining. The case was such that he was a property agent for plots of land, however, one of the scheme he was selling for was not completed on time and the main property scheme owner turned out to be fraudulent somehow. So the buyers started harassing my father and filed a case against him though he was just an agent. But my father got scared of jail to an extent that to get the bail, he surrendered and gave in writing he would pay off the money. He was paying as and how he could and was getting extensions from court. Before few months, he had got a last extension until 31st may from high court of Gujarat. However, the amount is still not arranged. What could be the outcome if he is unable to pay the remaining on the due date? Or what should he do to save himself from going to Jail?