Advice On Present Status

My Father-in-law made a Sale Agreement in 1987 for 8016 sq ft of property in Pondicherry for a price of Rs 3,60,000 and an advance of Rs 80,000 was paid and Sale Agreement registered for payment of balance Rs 2,80,000 within 6 months. When the party did not come for Sale, OS 202/1988 was filed. The Court ruled that there was an earlier WILL giving 50% share to another brother (though the WILL was not shared at the Sale Agreement) and only half the property can be sold but at the same price of Rs 3,60,000. The matter was taken to Madras High Court for permission to pay lesser amount (only half the value that is, Rs 1,80,000 - Rs 80,000 = Rs 1,00,000) or to Stay the proceedings of OS 202/1988. The Madras High Court ruled that they would need to go through the facts to decide on payment of lesser amount and granted a Stay of proceedings of OS 202/1988 in 1991. The decree of OS 202/1988 stated that my Father-in-law pay the balance of Rs 2,60,000 for half the property. Please note that by calculation it should have been Rs 2,80,000. As there was no progress in the Case and due to failing health, my Father-in-law withdrew the Stay in 1998 and within 10 days paid the balance of Rs 2,60,000 as stated in the Decree of OS 202/1988. As the party still did not come forward for Sale EP 210/1999 in OS 202/1988 was filed. When the case about to be decided Ex Parte, the party filed EA 580/2004 primarily indicating that there was a delay of more than 6 years in making payment of balance amount and that it was done with malafide intention because the property price had gone up. The case was dismissed indicating that both parties were represented by their Counsel in the Stay which was absolute, and no relief was asked by the party at any point during the Stay. Subsequent to the dismissal of EA 580/2004 in EP 210/1999 in OS 202/1988 we got a Court ordered Sale Deed done and Registered the property in our names on 03/04/2019 (legal heirs as my Father-in-law) had passed away. The other party has now filed a CRP in Madras High Court with the main contention being that the balance amount that we paid (as in decree of OS 202/1988) was Rs 2,60,000; whereas we should have paid Rs 3,60,000 - Rs 80,000 = Rs 2,80,000. That is, there is a shortfall of Rs 20,000. Obviously the calculation in the decree of OS 202/1988 was incorrect, but we had paid the balance as per decree after taking permission to deposit the amount in court and giving Notices as required. This point is clarified in Judgement of EA 580/2004. The case is presently under litigation as CRP 3088/2019, filed under Article 115 of the Constitution of India. While the case was under adjudication in Pondicherry, the other party had made Sale Agreement through a Power Agent, and actually sold half the property to a third party who has filed IA 07/2021 in OS 125/2021 in Additional District Munsif at Pondicherry under Order VII Rule 1 and Rule 2 R/W Section 26(1) of CPC.