but could he eat potatoes as in south indian bramhins do not eat onions or garlics
Answer
No. In Jainism, potatoes are generally not eaten because they are root vegetables.Explanation
Jains avoid:- Potatoes
- Onions
- Garlic
- Ginger
- Carrots
- Other underground roots and tubers
The main reason is that uprooting such foods destroys the whole plant and is considered to involve more harm to living beings.
So even if some South Indian Brahmins avoid onions and garlic, Jain dietary rules are usually stricter than that.