Legal advice to buy flat

Dear sir, Recently I booked one flat in Ulwe Navi Mumbai. But now I came to know one civil suit is active on that property. Conditional OC is recieved of the property from CIDCO. The case details is as below, Kindly note names are changed. CIDCO Plot was allotted to Mr Dheeraj but he made an agreement with name of her wife Shalini & son Ashish, Dheeraj have two children (Ashish & Ranjana), Ashish & family have made a tri party agreement with CIDCO & builder (12.5 %) in 2010. & Builder have completed the construction in Dec-2014. At present Dheeraj, Shalini (his wife), Ashish (son), Ranjana (Daughter) all are no more. Now, suit was filed by daughter of Ranjana (Daughters daughter) against Navin (Sons son) , Builder & CIDCO saying that she has not get any compensation against that property in 2012. Builder is saying that this is not a major issue & you can still buy flat as HDFC is providing the loan. My question is should I buy this property? Kindly answer me as soon as possible. Regards, Pankaj Agrawal.