It has come to the notice of the Central Government that foreign nationals are buying immovable property illegally in some parts of the country, particularly in Goa, which has raised concerns . . . [A]ll, including the authorities concerned in the State Governments, are hereby advised to be extra vigilant in such matters and satisfy themselves about the eligibility under [the Foreign Exchange Management Act] before registering a sale or purchase of immovable property in India. The enquiries [sic] may include both the intending buyers and sellers. The relevant travel documents and the nature of visa may also be verified before registering such sale / purchase.