Fruit is fine at any time, but only eating fruit for a meal may not satisfy hunger.
You need to have a balances meal for lunch or any other. For example: some chicken or beef, some rice, potatoes or bread and vegetable or fruit. Your body needs one of each of the three categories to feel good and with energy. So, your curry and rice seems fine if you you have some chicken, fissh or meat mixed in the curry and a piece of fruit would be a balanced meal. Instead of fruit you can have vegetable such as carrots or salad or broccolli. Good luck.
In principle you are correct, but it is the balance during the course of a day that counts. My favorite summer lunch is a bowl of mixed berries, with a sliced banana - the whole thing smothered in heavy cream. I can eat meat and vegetables at the other meals.