Biscuit base - Grease the sides of a 7 inch removable cake pan and line the bottom with parchment paper. Combine biscuit crumbs with melted butter. Pressing the biscuit crumbs with your hand at the bottom of the lined cake pan. Place the cake pan in the refrigerator for later use.
Cream cheese filling - Sprinkle gelatin over orange juice (stir well) in a heatproof bowl for about 2 minutes. Add orange zest on top of gelatin and place the bowl over boiling water until gelatin dissolves, stir well.
Place all the cream cheese filling ingredients together with melted gelatin in the food processor, and blend mixture until smooth. Add some mandarin orange pulp into cream cheese mixture and stir well. Pour cream cheese mixture into the prepared cake pan. Chill to set for at least 2 hours or overnight.
Topping - In a small pot, boil topping ingredients together and stir well, and set aside to cool down for about 2 minutes. While waiting for the jelly liquid to cool, place mandarin oranges on top of cheesecake. Gently pour jelly liquid over mandarin segments. Return to fridge and chill for about 1 hour until the jelly is set.