is a new character introduced after script reformation in 1970's. The Traditional Charactar for long /i/ as derived from Grantha is .
ऎ ऒ ऩ ऴ ऱ - These are all new modern characters proposed in ISCII to faciliate Transliteration of South Indian scripts into Devanagari.
Bengali lacks the letter for /va/. Assamese ৱ has been used to represent /va/. Also, the equivlent letter for the Tamil/Malayalam ழ has been created by placing the nukta on /sha/ ষ
Oriya doesn't have /va/ like Bengali. However modern Oriya uses ୱ to denote the /w/ sound. It has been used as an equivalent for /va/.
Sinhala traditionally uses the short vowel /e/ and /o/ to denote long /e/ and /o/ in Sanskrit/Pali texts. The long vowels are used only in Sinhala text.
Tamil publishers generally use a system of superscript/subscript numerals to denote the Sanskrit Varga consonants which the Tamil-Script lacks. The same is used here. Just the characters for R, RR, L, LL, Anusvara & Chandrabindu.
Grantha traditionally lacks a Nukta. It is proposed as a new addendum to the Script.
It is a hybrid between Tamil-Grantha script used by some publishers in Tamil Nadu to print Sanskrit texts.
Telugu Letter ఁ though named as Chandrabindu in Unicode, is not the real Chandrabindu. It is called Arasunna, and is a prosodical character. There are some modern texs use this character as the equivalent of Chandrabindu when writing Hindi in Telugu Script. I have for now used this character as the equivalent for Chandrabindu. There real Chandrabindu is in pipeline for inclusion in Unicode (along with Malayalam and Kannada Chandrabindu-s )
The symbol for Visarga as mutated to a vowel sign for short a (Sara a). I have just shown the Visarga using a colon (:)