As this is the Swyama Siddha Hanuman Mantra it doesn't have being chanted for a hard and fast range of Mantra Repetitions for with the ability to utilize it. Unique worship and rituals and rules regarding way, sitting down mat, and counting rosary are usually not advisable for chanting this https://www.youtube.com/watch?v=ufkmD95y7fE&t=32s