Landowner entitled gst collection/filling jv or dev.agreem

 If the land owner gets 50 % of Flats (3 out of 6) from Developer, (as per Dev.Agreement / JV), and   further as per the same, land owner sales  those 3 to different home buyers , who is entitled to get GST (either 12 % or 18%)from those home buyers, either Land owner or Developer? Further is land owner is liable to fine GST returns? as developer will be showing / filling his GST returns on purchases of  building materials and services on ENTIRE 100% or 6 flats