As that is a Swyama Siddha Hanuman Mantra it doesn't have for being chanted for a hard and fast number of Mantra Repetitions for having the ability to utilize it. Special worship and rituals and principles relating to direction, sitting down mat, and counting rosary aren't recommended for chanting this https://directoryunit.com/listings13048822/not-known-details-about-hanuman-shabar-mantra-get-rid-of-all-problems