Heat oil in a deep-fryer or large saucepan. Deep-fry okra, 5 at a time, in hot oil until softened and dark green, about 5 minutes. Drain on a plate lined with paper towels.

Place tomatoes and ginger in a food processor; grind into a paste.

Heat 3 tablespoons oil in a large skillet over medium heat. Add cumin; fry until golden, about 30 seconds. Stir in tomato-ginger paste, salt, chile pepper, turmeric, mango powder, coriander, and garam masala. Cook until oil separates and sauce thickens, 3 to 5 minutes. Add yogurt; cook until oil separates again, about 2 minutes.

Pour in water and bring sauce to a boil. Add fried okra. Reduce heat to low, cover, and cook until flavors combine, 5 to 6 minutes.