* "Paatti" (பாட்டி) - This is the most common term and refers to a grandmother on the mother's side.
* "Aatchi" (அச்சி) - This term is used to refer to a grandmother on the father's side.
You can also use "Thaayaamma" (தாயம்மா) or "Aappaamma" (அப்பம்மா), which literally mean "mother-ma" and "father-ma" respectively, as more affectionate terms for grandma.