Land purchase with section-143 approved

Hello Experts, I am going to buy a land of 100 sq yards in Ghaziabad which is not GDA approved but as per seller it is section 143 approved and non agriculture. Kindly advice me on the following queries As per seller I will get only registry of the plot. Can I get mutation on that plot anyhow ? I heard that some of the cases that properties were sold to multiple buyers as a fraud registry. What is the mean of registry than ? How can we get genuine registry ?