How to give delay() in a c program in linux operating system.
 

Please advice me how to include a delay in my parallelised c program in linux os.

I assume that 'parallelised' means, you are writing a multi-threaded application. If you want one of your threads to wait for a while, you can use sleep() or nanosleep(). Depending on the multi threading environment you use, there might be more specific functions.
Ask yourself if you really need a delay or if you better should use a mutex or a semaphore instead.