I’ve heard English people call him rama-NEW-jin, but most Americans I’ve heard call him ra-MON-uh-jon. Which is correct? (Or is it neither?)
The wiki leads me to believe that the english pronunciation is closer, but I don’t know on what basis, wiki is making its choice regarding pronunciation.
On the TV series Numb3rs, one of the characters was named Amita Ramanujan. They pronounced it rah-man-oo-zhahn, accent on the second syllable.
Here’s Ramanujan pronounced by an Indian speaker in an Indian documentary.
Here’s how Ramanujan is written in the Devanagari script: रामानुजन्
Which breaks down as:
रा = र + ा = r(a) + aa (long a) = raa
मा = म + ा = m(a) + aa (long a) = maa
नु = न + ु = n(a) + u (short u) = nu
ज = j(a) (short a - if vowel is not written it’s short a) = ja
न् = n(a) (+ virama, which is the little diacritic line at the bottom of the letter which cancels the inherent vowel of the na consonant, making it Ramanujan and not Ramanujana) = n
So “rama-NEW-jin” would be a closer approximation of the pronunciation, although i is a different vowel altogether. The Devanagari small a of the “-nujan” part of the name is the sort of default vowel and is weakly pronounced, perhaps comparable to the sound of the a in “human”.
Missed edit window. On Numb3rs a character with this name pronounced it rah-MAH-noo-zhahn.
His name could be Rahman Uzan. Rahman is an Arabic name with the stress on the “-man” as heard here. Uzan is, I think, a West Asian surname. Googling “Rahman Uzan” brings up people with that name.
IMDB shows the character in Numb3rs to be Ramanujan (rather than Rahman Uzan!). Clearly the pronunciation of someone’s surname can change, especially in a different country, Charlize Theron being one such example.
An Indian pronunciation of Ramanujan would have both the a’s in “Rama” as equally stressed. One can hear the pronunciation of “Ramayana” (रामायण), the Indian epic poem, here. Ramayana uses the same letters (रामा) for “Rama” as Ramanujan does, and one can hear that they have equal weight. The Devanagari small a is transliterated as “uh” in this example.
This article from the Scientific American website says that the British pronunciation is Raman-UJ-an, but the Tamil pronunciation is Ra-MAN-ujan, and Tamil is the language that Ramanujan grew up speaking:
Here’s a couple of Indians saying Ramanujan’s name, one North Indian and the other Tamil. They both pronounce Ramanujan the same way: rAmAnujan. The stressed vowels are the first two a’s, since they both use the long forms of the vowels, while the u and final a use short vowel forms.
That said, I don’t know much about the Tamil language and maybe they have different pronunciation locally.
As a Tamil mathematician, I say, just listen to this clip. In particular, don’t make the last syllable “zhahn”; start it with a normal English “j” sound.
Her. Amita Ramanujan. She’s Tamil.
Thanks - sounds like the British people I’ve heard are right on the money.
A BBC commentator’s pronunciation: COURTESY BBC DOCUMENTARY ON RAMANUJAN -Legendry Indian Mathematician -with subtitles-Ravish Physics - YouTube
Thanks, Nanoo. May I assume you are a fan of both the Orkans and the Bajorans? 
The name is derived from Sanskrit “Rama” (the deity-hero of that name) + “anuja” “later-born”, i.e., the younger brother of Rama, namely the hero Laksmana.
Which is correct. That’s because, as you noted, the “a” in the syllables “Ra” and “ma” is long, so the syllable is heavy in both cases. The syllables “nu” and “jan” are light, since they have short vowels and no double consonants. So the heavy syllables get the stress.
The common western pronunciation “Rama-NU-jan” probably evolved in erroneous imitation of more familiar four-syllable non-Indic names such as “Alexander”, “Amadeus”, “Obadiah”, etc.
I have always thought his name ended with an ‘m’ not an n. That is, Ramanujam.
That’s an attested alternate form. The Sanskrit stem form of the name is Ramanuja. Such names usually get a final nasal consonant when adopted into Tamil, and the nasal can be rendered as either -am or -an.
I am from the same (Tamil Brahmin) community that Ramanujan comes from I can attest to the fact that for us, Ramanujan does not roll off the tongue as easily as Ramanujam.
The trouble with expressing pronunciation in terms of other words, is that your audience may pronounce those other words differently.
I would be surprised if anyone said it as rama-NEW-jin, I thought the common pronunciation was rama-NOO-jin.
It may be spelt Ramanujan, but it’s pronounced “Throatwobbler Mangrove.”