Crush the biscuits to a coarse powder and plate in a bowl. Add the butter and mix well. Place the mixture in a six-inch round spring-form pan (loose bottom tin) lined with greaseproof paper. Press the mixture lightly and place it in the refrigerator to set. Heat the milk in a pan. Add the condensed milk and mix. Mix the cornflour with a little milk and add it to the hot milk. Cook stirring continuously till the mixture thickens. Set aside. Mix the carrageenan in a little water and heat in the microwave for one minute. Remove and set aside. Place the drained yogurt in a bowl. Add the paneer and whisk well. Add the mango pulp and mix again. Add the mango essence and the milk mixture and mix again. Add the powdered sugar and blend with a hand blender. Add the dissolved carrageenan and blend again. Pour the mixture into the prepared tin over the biscuit layer. Refrigerate for two to three hours. Dissolve the mango jelly in a quarter cup of water, bring to a boil and cool. Spread a layer of mango jelly on the set cheesecake. Chill until the jelly is set. Remove from the spring-form tin and cut into eight wedges with a sharp knife dipped in hot water. Serve chilled decorated with chopped mango.