For your mother's mother:
* Kurmanji: Dê
* Sorani: Nana
For your father's mother:
* Kurmanji: Dê-Bav
* Sorani: Bê
These are the most common terms. However, there are other variations depending on the region and family tradition.
Here are some additional options:
* Kurmanji: Apê (grandmother in general)
* Sorani: Mam (grandmother in general)
It's always good to ask a native speaker for confirmation if you're unsure about the specific term used in their region.