How can I transfer the GPA to my mothers name?

Hi,

My father had a residential land in Merrut. The only document which we have at this point of time is a GPA in the name of my late father, given to him by the seller. This is a notarized GPA.

My father passed away few years back. So please let me know how can I get this property transferred on to my mothers name?

Thanks, GS
This was purchased from a Private Builder in Merrut, India.

So in this case at this point of time who is the owner of the plot?