Can one survey number has property belongs to many people ?

Hi Sir, I am planning to buy a resale plot developed by a private builder and was purchased by a party “A”. Developer has purchased properties from many people in a village and formed a residential layout after converting it into non-agricultural and taking necessary approvals from residential planning authority. I got the copy of sale deeds where builder has purchased from owners. The plot has survey number 120/5. As I checked there are two sale deeds stating two distinct dimensions of land on the same survey number belongs to X and Y persons. Plot number 150 is in 120/5 survey number, but I don’t know that on whose land(X or Y) the site is located. The first purchaser of the plot has got sale deed from builder stating plot number 150 is located on 120/5 that’s it. More worrisome is, after 7 years someone(Z) has filed a case against developer under SC/ST act and got another dimension of the land transferred to his name for a period of 1 year. After that builder has got the property back on his name. The current owner of the land id builder. Can same survey number has land belongs to many people? Please advise is this plot purchase of safe? How can I get to know that plot 150 belongs to whose land(X or Y or Z)?