Yes, many Jains can eat dosa if it is made in a Jain-acceptable way.

Generally acceptable if:

• it has no onion, garlic, potato, or other root vegetables
• it has no egg or meat
• it is prepared with clean, non-violent care

Sometimes avoided by stricter Jains if:

• the batter is fermented overnight
• it is made in a place where non-Jain ingredients are used
• it contains ingredients not accepted in one’s family or tradition

So, plain dosa can be Jain-friendly, but it depends on the ingredients and the specific Jain tradition or family practice.