That's a good question! In Australia at the moment a Chinese mining house has bought 43 large farms at the moment due to a loophole in foreign investment regulations. Of course this has caused some alarm as no one wants to see good farming land being turned into a mine owned by outside interests who may not have the environment of the local community's interests at heart.
I am sure that you don't have this in mind when you are talking about farming land in New Zealand, but I am sure that they too have a regulatory body for foreign investors that may not allow you to buy certain properties.
If you want to immigrate to New Zealand and qualify through their point system, and then buy a farm, this would be possible as you would then be a resident. But if you were to stay in India and buy the farm as foreign investment that may be a different matter entirely.
Perhaps someone else can throw some light on this topic?