Bring jackfruit, jaggery, and water to a boil in a small saucepan; cook until jaggery dissolves, about 10 minutes. Let cool, about 10 minutes.
Transfer jackfruit mixture to a large bowl. Add milk, oats, egg, and baking powder; stir until batter is well-combined.
Heat a nonstick skillet over medium heat. Drop 2 to 3 tablespoons of batter onto the skillet, using the back of the spoon to spread batter evenly into a round. Cover with a lid and cook until pancake is browned, 1 to 2 minutes per side. Transfer to a serving plate.