Try deleting the applications from your Apps collection via iTunes. In this situation, you'll need a Windows or Mac computer with the most recent version of iTunes installed, and then follow the procedures below:

1. On your PC, launch iTunes.
2. Using the included USB cable, connect your iPhone 6s to your computer.
3. To continue, wait until iTunes recognizes your iPhone or press the option to Trust This Computer.
4. From the list of iTunes devices, choose your iPhone 6s.
5. Go to the Apps section of your library (iPhone Apps).
6. Press the Delete key on your keyboard after selecting the programme you wish to uninstall.
7. If prompted, select Delete from Library to complete the operation.