Currently I am using i.MUX6Ul evk board. I want to run RTOS on it. It is having cortex-A7 architecture. Does freeRTOS available for the same?
How easy this will be depends on the interrupt controller used. If its a standard ARM GIC then you can follow the information on this page:
and you can use the Zynq demo as an example (doesn't matter that the Zynq is A9 rather than A7):
If your chip has a proprietary interrupt controller then you can follow the information on this page:
and use something like the SAMA5 demo as an example: