Ancestral Property been auctioned without knowledge of legal heir

Hi I am Sivakumar and i am writing this question on behalf of my uncle Nagaraj as like he writes as below. Hi I am Nagaraj from Tirupur tamilnadu. We had a ancestral property of nearly ten acres. At 1966 my grandfather partitioned the properties into two for his two sons Natarajan and Vinayagappan and my father Vinayagappan got nearly four acres in it at the year 1966 the partition done . Vinayagappan have myself one son and three daughters named Kousalya, Kanagam and Banumathi. At the time of partition we all are minors. At the year 1970 my elder sister kousalya got married to one of my relative named Ranganathan. At the same year a case OS has been filed by Kousalya on her father vinayagappan as that vinayagappan has borrowed a sum of 1500 rs from her and failed to pay her and a judgement came as to pay the borrowed amount plus interest and court fee totally of 3001 rs. But vinayagappan my father failed to pay that too and an EP has been filed by my sister Kousalya attaching all the properties of vinayagappan and an auction held by the court and the properties were been purchased by ranganathan the husband of kousalya . At the time of auction i am a minor and my other elder sisters were unmarried and we all living as a joint family. But without our knowledge our ancestral properties been auctioned and we don't know about this as we all were at our childhood at that time. We thought all the properties were been maintained by my elder sister's husband and they have been said that all our properties have been given as gift deed to my sister kousalya. As we were at our childhood we don't concern about this and we were really out of knowledge of this. My Sister's husband ranganathan changed all the properties into his sister's husband name and his sister's husband sold all the properties to another relative of his. All these things we came to know last year by one of my Sister Kanagam's Son Sivakumar. As myself and sisters were not well known about the law and other terms we lived as that all properties been given to my elder sister kousalya. But as we came to know about this that our all properties were been tricked threatned my father and been got by my sister's husband ranganathan all of us shocked . My question is can we able to file a partition suit now for my ancestral property which has been auctioned without our knowledge.Any one give us a right way to proceed this.