UDS & LOAN ON MOTHER DOCUMENTS

Dear sir,

A builder for constructing 6 FLATS (ground 3 + 1st Floor 3) on a 2400 sqFT of land area. He sold his 2400 sqft of land for six people as UDS on behalf of six flats constructed on that land. He sold approximately around 320 sqft each to six owners. The total he sold is 2000sqft. Since one of the person wanted to sell his flat to another person, he seek the help from the builder. So the builder again sold a 320 sqft to me saying that he is selling this Flat as a new flat and never told the details about his previous registrations.

My question here is the flat which i bought is FLAT no:6, this is already sold as UDS to one person before me. Is there any chance that the previous one who possesses the UDS has the rights on my flat? Or else if he doesn’t pay the loan back borrowed on those UDS, will the bank claim my property on Depts Recovery Tribunal.

Dear sir,

If the builder in 2006 has cancelled the registered sale deed done in 2005, then will the registration done in 2005 will still appear in the EC?

If this is the case wy the cancellation is not appearing in the EC? what should be the proper way to apply for a EC to get the previous registration, cancellation and my new registration in my name. please help me with a quick response, since iam planning to sell my Flat.