As per section 2 sub section 1A agricultural income includes income from rent by letting out agricultural land used for agricultural purpose.
Therefore your income is exempt as agricultural income.
However you will have to enter into an rent agreement which would clearly mention that the land is agricultural land used for agricultural purpose as income tax officer won't accept verbal agreement.
Also if your tenant is doing agricultural activities i.e. growing some food grains then I guess gram panchayat or local mandi also issues a form where they mention the crop grown and the land on which it is grown details rate of the crop etc, you must also keep that as a proof.
This two things would be great to prove your agricultural income.
So just fulfill above requirements and relax.
Hope this helps.
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