Great grandfather ancestral property(paternal) sold by father without my consent!

My name is Raghu and I'm 38 years old Married and blessed with 2 daughters. The ancestral property of agriculture land(44 acres) came from my great grand father(Paternal side) has been sold by my father without my consent while I was a minor, signing on a normal document but the purchasers have registered the land in the recent times. This was completely kept away from my notice and when I started checking the records to claim my share in it, this has come to my attention that the land has already been sold to someone. I strongly feel whatsoever it is injustice to sell my ancestral property without my consent, that didn't even helped me in my tough situations. I feel my parents would have saved some of my ancestors property at least so that it would have helped me and my family members in many ways. Out of 44 acre land sold, 1.75 acre land has been registered by the purchaser illegitimately without my dads consent and faked the signature on the final document of registration Please advice. Thanks!