That's hard to explain since the most phonems of this name are not present in English. The N is soft, just like you are trying to say "ny" in "nyam nyam". Then come "ePOM" (i.e. the stress is on POM, the P is without breath out) then again the soft "n" (which is transliterated as "ni" here) then "a" (very short, almost unhearable "uh") and here comes the most difficult sound, the "chtch". To pronounce it, you prononunce "sh" placing your tongue not on the under the upper alveols like in "sh" but on the same place behind the under teeth. And "i" is clear.