While you can use self-rising flour for frying, it's not the best choice and may not yield the desired results. Self-rising flour contains baking powder and salt, which can affect the texture and flavor of the fried food.
When you fry with self-rising flour, the baking powder in the flour can cause the coating to puff up more than usual, resulting in a thicker and less crispy crust. Additionally, the added salt in self-rising flour might make your fried food taste saltier than you intend.
For optimal results when frying, it's better to use all-purpose flour or a flour specifically intended for frying, like a fine-milled, low-protein flour often labeled as "fry flour" or "frying flour." These flours create a lighter and crisper coating on the food without any additional leavening agents or salt.
If you only have self-rising flour on hand and don't want to go buy all-purpose flour, you can still use it for frying, but keep in mind the potential issues with texture and flavor. Adjust your recipe and seasoning accordingly to accommodate the self-rising flour's baking powder and salt content.