|Devanagari|ISO 15919|UNRSGN|IAST|Comment|
|---|---|---|---|---|
|ए /  े|ē|e|e|To distinguish between long and short 'e' in Dravidian languages, 'e' now represents ऎ /  ॆ (short). Note that the use of ē is considered optional in ISO 15919, and using e for ए (long) is acceptable for languages that do not distinguish long and short e.|
|ओ /  ो|ō|o|o|To distinguish between long and short 'o' in Dravidian languages, 'o' now represents ऒ /  ॊ (short). Note that the use of ō is considered optional in ISO 15919, and using o for ओ (long) is acceptable for languages that do not distinguish long and short o.|
|ऋ /  ृ|r̥|ṛ|ṛ|In ISO 15919, ṛ is used to represent ड़.|
|ॠ /  ॄ|r̥̄|ṝ|ṝ|For consistency with r̥|
|ऌ /  ॢ|l̥|l̤|ḷ|In ISO 15919, ḷ is used to represent ळ.|
|ॡ /  ॣ|l̥̄|l̤̄|ḹ|For consistency with l̥|
|◌ं|ṁ|ṁ|ṃ|ISO 15919 has two options about anusvāra. (1) In the simplified nasalization option, an anusvāra is always transliterated as ṁ. (2) In the strict nasalization option, anusvāra before a class consonant is transliterated as the class nasal—ṅ before k, kh, g, gh, ṅ; ñ before c, ch, j, jh, ñ; ṇ before ṭ, ṭh, ḍ, ḍh, ṇ; n before t, th, d, dh, n; m before p, ph, b, bh, m. ṃ is sometimes used to specifically represent Gurmukhi Tippi  ੰ.|
|◌ं|ṅ ñ ṇ n m|ṁ|ṃ|ISO 15919 has two options about anusvāra. (1) In the simplified nasalization option, an anusvāra is always transliterated as ṁ. (2) In the strict nasalization option, anusvāra before a class consonant is transliterated as the class nasal—ṅ before k, kh, g, gh, ṅ; ñ before c, ch, j, jh, ñ; ṇ before ṭ, ṭh, ḍ, ḍh, ṇ; n before t, th, d, dh, n; m before p, ph, b, bh, m. ṃ is sometimes used to specifically represent Gurmukhi Tippi  ੰ.|
|◌ँ|m̐||m̐|Vowel nasalization is transliterated as a tilde above the transliterated vowel (over the second vowel in the case of a digraph such as aĩ, aũ), except in Sanskrit.|

Question: how many total options are there about anusvara?
Answer: 2