Place the converted folder in Hdd1:\Content\0000000000000000\ .
If you have downloadable content, it must be placed in the internal drive: Content\0000000000000000\[TitleID]\00000002\ . Kung Fu Panda [Jtag/RGH]
Xbox 360 ISO files cannot be played directly on JTAG/RGH. You must convert the ISO using one of these tools: Kung Fu Panda [Jtag/RGH]