Here is the pronunciation of each word in Japanese:
* Nam: nahm (like "nam" in "name")
* Myoho: myo-ho (with a long "o" sound, like "moe" in "mode")
* Renge: ren-ge (like "ren" in "rent" and "gay" in "game")
* Kyo: kyo (like "key" in "key")
Therefore, the entire phrase is pronounced: nahm myo-ho ren-ge kyo
If you are interested in the Sanskrit equivalent of the Lotus Sutra, it would be "Saddharma Pundarika Sutra" which is pronounced:
* Saddharma: sat-dhar-ma (like "sat" in "satin" and "dharma" like "drama" but with an emphasis on the "a" sound)
* Pundarika: pun-da-ri-ka (like "pun" in "punch" and "ri" in "rice")
* Sutra: soo-tra (like "soo" in "soon" and "tra" in "train")
So the entire Sanskrit phrase is: sat-dhar-ma pun-da-ri-ka soo-tra