Land Dispute after registration.

I have bought a ghramakantam land 10 cents(Area) from a person(Ravi). His father is Actual owner of the land who bought that same land from another one long back ago (around 40 years back).Ravi’s father died 8 years back. All tax payment receipts to Ghramapanchayt on that land are in His Father’s name. at 40 years back there are no registrations on ghramakantam lands. We paid total cash in two installments. In first installment Ravi and his mother signed on 100 Rupees stamp paper by as proof. In second installment we directly gave money to his mother and didn’t amend that paper. Due to restriction in ghramakantam registrations in AP there was a delay in land registration.Now government is allowing to register ghramakantam lands. We prepared for registration but Ravi was hesitated to Register land . But Ravi’s mother and 3 sisters are registered land on my name joined as parties. After 3 months Ravi made another move . he played a trick, register same land to his wife (Aruna) from old owner of that land(40 years back owner’s daughter) . With that registration he occupied that land. He is on that land now. I have few questions here. 1) Is that second registration is legal? 2) How can is proceed to take over the control of that land into my hands? Please suggest me how can I proceed legally.