A Letter of Intent (LOI) is a document issued by GMADA (or other development authorities) confirming that a specific plot has been allotted to you. It is not the final sale deed — that comes after infrastructure development and possession. However, LOIs are freely tradeable in the secondary market. When you "buy a plot in Aerotropolis" you are typically buying an LOI. The actual registry happens years later after the authority completes roads, utilities, and issues a possession letter.