I have a NXP LCPXspresso 1768 board with mx-based board and want to running your demo on the folder of CORTEX_LPC1768 Is it the right board for the demo ?

I’m not sure which demo you are referring to. There are a few LPC176x demos, but none with that directory name: https://sourceforge.net/p/freertos/code/HEAD/tree/trunk/FreeRTOS/Demo/

the demo is: https://sourceforge.net/p/freertos/code/HEAD/tree/trunk/FreeRTOS/Demo/CORTEXLPC1768IAR/​

According to the documentation page for that demo the hardware is a KSK-LPC1768-PL Kickstart Kit from IAR – which I doubt is available any more.