How to challenge a will when I have been adduced as a witness.

My father is traceless since 2004. I never knew the reason of this but my mother always said that he was burdened by debts and hence absconded the society. I was minor at that time. In the year my paternal cousins(father's sister) filed a suit for partition of the property as the property was in the name of my grand father who died in 1985. In order to avoid that partition, my mother forged a will and filed L.A Case relating to the property. In 2011 after being major, I was adduced as a formal witness in the same L.A case but only as a formal witness regarding being traceless of my father. I didn't knew about the forged and fabricated will that time. Nothing regarding will was adduced by me. Only two lines regarding my DOB and study and father being traceless since 2004 was submitted by me. Now in 2018, I came to know that the will is forged and fabricated and my mother did all these to sell property and deprive me of my rights. I filed an intervention petition for being added as opposite party in L A Case but was rejected as I have been cross examined as AW-9 . What should I do now. Moreover I came to know that my mother was the culprit behind leaving the house and society by my father. She didn't inform police about his absence at that time or later. What should I do now.