What land grabbing looks like in practice
It is rarely a single dramatic act. More often it is a sequence: an occupier is placed on the land, a compound wall goes up, a forged power of attorney or sale deed appears, and by the time the owner learns of it there is a registered document and a person in possession.
Owners living outside Chennai, NRIs especially, are disproportionately affected, because the absence of anyone checking the property is precisely what makes the sequence possible.
The two tracks, and why both are needed
Neither remedy is sufficient on its own, and the sequencing is what determines the outcome.
Protecting property before anything happens
For owners of vacant land, prevention is cheap compared with litigation. Keep property tax and EC current, fence and board the land, have it physically inspected periodically, and register a caveat where a dispute is anticipated.
For NRI owners, a properly drafted and narrowly worded power of attorney given to someone accountable is far safer than a broad one, and a periodic encumbrance certificate check will surface an unauthorised registration long before a site visit would.