What it is
Natham refers to the built-up core of a village — the house-site area — as distinguished from the surrounding agricultural survey numbers. Villages in Tamil Nadu typically have a natham boundary drawn around the residential settlement, and land within it is treated differently from nanjai or punjai fields outside it, since it isn't assessed for agricultural revenue. Older natham plots sometimes lack the same individual survey-number subdivision that farmland has, which is one reason natham properties can have a different documentation trail than agricultural land nearby.
Why it matters when you buy
Because natham land was never assessed as agricultural land, some natham plots — especially older ones occupied for generations — may have a thinner paper trail than surveyed farmland, with patta or ownership documents that took longer to formalize. If you're buying a house or house site in a natham area, it's worth checking the specific patta-chitta and any past patta-transfer history for that plot rather than assuming the same process used for agricultural land nearby. Ask the taluk office and local revenue staff about the plot's specific record status.
Where you find it
A plot's natham status is reflected in how its survey number and patta are recorded at the village level, and the village's natham boundary itself is a revenue-department demarcation rather than something printed on your patta directly. For a specific plot, the patta-chitta and the A-register are where you confirm how the land is classified and assessed; local revenue office records will show whether a given house site falls inside or outside the mapped natham area.