What is the correct way of saying Nabi in the plural form?

Question
What is the correct way of saying Nabi in the plural form?  Taking into account the rasm Alif Nuun Bey.... some people pronounce it is Anbiya using the first 3 Rasm alphabet whereas others pronounce it Ambiya.  Is there a technicality involved using Tajweed or this an error?

Answer
There are actually two forms of pluralizing the word , which can have a dhammah as the last vowel, or a fathah, or a kasrah, depending on its grammatical place in the sentence.  The first form of pluralizing is a regular form, which is , or ; and the use of one or the other is dependant on its grammatical place in the sentence. 
The other form, which is irregular, is , and this is the word referred to in the question.  There is a saakinah followed by a , and in taweed rules, when this case exists, the saakinah is changed into a and the is hidden by closing the lips on the meem, holding it for the length of time for the complete ghunnah, then the lips are separated while pronouncing the .  So one can spell it in transliteration into English letters using the written letters, al-anbiyaa', or the correct pronunciation of the letters, al-ambiyaa', whichever one prefers. 

Please also see: http://www.abouttajweed.com/the-noon-saakinah-and-tanween/changing-iqlaab-rule-of-the-noon-saakinah-and-ta.html