Hi Anuja,
Sorry, it has been a very long time since I last worked with the PRU. I honestly don’t remember. Maybe some more googling around will help?
Have you tried this? http://elinux.org/ECE497_BeagleBone_PRU#Building_and_Running_the_GPIO_PWM_PRU_Example
I got a fair bit of information from the elinux.org wiki. I’m not sure what’s right, but I would try getting that example working in the link above, and try to figure out what’s different between your code and the example code that stops it from working.
Don’t ignore search results with ECE497; it’s the class ID for embedded linux at Rose-Hulman. We worked with Beaglebones there.
Good luck!