Hiding earlier Decree and got ex-party decree

Respected Sir, My grandfather had purchased the property extent of 15 acres in 4 survey Nos in 1967. he has 3 sons & 2 Daughters. Grandfather was in possession and enjoyment of the above property. after purchase, the defendant ( neighbour) age28 had begun to lay claim that his family from time immoral ,have an extent of Acres 3.01 in the one survey field and he and his brother had entered into a deed of partition thereby he had been allotted 2.86 acres and his brother had allotted 0.15 acres and had tried to interfere with my grandfather’s possession and enjoyment of the same. So my grandfather had filed a suit in 1969 in District Munsif of Coimbatore for declaring for his title to the suit property and for permanent injunction. After hearing both parties, in 1971 ,the Hon'ble court passed judgment and decree in favor of my grandfather declaring that grandfather is the absolute owner of 4 acres in the suit property & restrained the Defendant from interfering in the peaceful enjoyment of the suit property by way of perpetual injunction. Aggrieved defendant preferred an appeal before subordinate judge of Coimbatore in 1972 against the decree and judgment , court dismissed the appeal in 1973. The defendant did not prefer any second appeal or revision. Grandfather died intestate in 1975 leaving behind his wife and 3 sons & 2 daughter. In the year 1977 , 3 sons of my Grandfather and his wife i.e my Grandmother had entered into a deed of partition of the above property and registered and have been enjoying the property, all the Revenue records are changed as per the Partition deed. Subsequently ,First son died in the year of 1988 leaving 3 daughters as his legal heirs. In 2005 my father died and leaving me as legal heir , last son of my grandfather died in 2005 leaving one son namely Sekar as his legal heir. In 2007 , the same defendant age 78 has filed the suit before IADM in Coimbatore against Grandson (i.e last son's son (Sekar)) alone as Grandson (sekar ) did not file his written statement and leaving other legal heirs and obtained Ex-party decree in 2008 hiding earlier decree. Other legal heirs came to know those incidents and ex-party decree recently in 2018 .But at the same time the defendant has changed all the revenue records 3.00 acres in his name in the above survey number through court commission. Everything has fraudulently obtained. Neither Govt surveyor nor advocate commissioner given any notice to other legal owners of the property and now he filed Execution Petition against Grandson and case is in live. Last year I have given a compliant in the respective police station against the defendant asking to take action against him for getting ex-party decree by hiding my grandfather decree . But police refused to take action as they told which is pending in civil court.I request you that possibilities to take action against this defendant either in civil and criminal proceedings. Can I file contempt petition