Bought a property that is in court unknowingly

I bought a form land recently, the registration is done a week back.The problem is, after registration, we got to know that it is under court dispute… Below are the form land details. It is 2.6 Acre land which I bought from Venu who is the only son of his mother.His father(Papi) had 2 wives(Wife1 - Veda, Wife2 - Rada). After first wife(Veda) is expired, married Rada(mother of this Venu). This Papi had a total of 6Acre land divided under two servey numbers(S1, S2) and a house.The land I bought is in S2 which is self earned by Papi. This 6 Arce land is self earned by Papi and house has come from his parents. At the time of marrying Rada, he has registered all of his property on her name(Rada). Veda had a doughter(Veena) and Veena has a son(Somu). Now this some is claiming the property that his grandma(Veda) also has right to get the property of her husband. Now, is there a possibility that this person Somu win the case and get some percentage of property ?? If yes, do I get any problem of getting my registration nullified ??? PS: Before buying we cross checked EC & at registration office, we found no legal issues. Please suggest how to proceed now.