Put the jack fruit flesh into a grinder.
Add the jaggery syrup. Grind to a smooth, fine paste. Transfer the mixture to a bowl.
Add the grated coconut, ground cumin, salt and rice flour. Mix well. Do not worry if the mixture is slightly liquidy. The rice flour will absorb the moisture.
Cover and keep aside for about 10 minutes.
Take a leaf. Fold it. Secure with a toothpick. the mixture into the cone. Fold the leaf and slip it along the inside of the cone. Continue the process till the entire mixture is used up.
Place the parcels on a steamer and steam for about 30-35 minutes or till cooked through. Serve warm.