Yes.. you can buy land in Karnataka if you are farmer any where in India. You should get RTC (Phani). And your/your family income should not exceed 2 lakhs per anum.
For getting Rtc certificate, u are an existing farmer in karnataka,
not assesed to income tax was another requirement.
If u interested means contact us we provide all these services according prevailing law/statute.
If u are not follow law means severe legal penal consequences like taking of ur land by govt and paying govt rate.