Devanagari is the "official" Script for Sanskrit these days. But Sanskrit per-se never had any official script. It was written with the local script of that region. But since the 19th century Devanagari has been projected as the sole script for Sanskrit. People seem to associate Sanskrit only with Devanagari, which is quite historically incorrect. Sanskrit was written with a variety of scripts in the Past, and also in the present. Devangari is one of the Major scripts used for writing in Sanskrit, and certainly not the only script !

Features of Devanagari Script

ISCII Extended Devanagari

Traditional Devanagari lacked characters for the South Indian Characters and stuff. When ISCII was proposed, Devanagari was extended and new characters were added so as to enable it to represent any Indian Language. Two new short vowels were Introduced for short /e/ and short /o/, by modifying the shapes of the existing long vowels.Characters for /LLLA/, /RRA/. /NNNA/, /YYA/ were also formed by extending the script using Nukta.

ऎ <short e> ऒ <short o> ऩ<NNNA> ऱ<RRA> ऴ <LLLA>

Marathi Eyelash Ra

Marathi use a  specific form of the Repha called "Eyelash Ra". In Unicode it is usually respresented as <RA> + <VIRAMA> + <ZWJ> . But due to compatibility with the ISCII standard, Unicode also represents Eyelash ra as the half-form of the dravidian RRA. (Compatibility with Legacy encodings is something which I don't like :-/ about Unicode )

Hence in Transliterated Devanagari text, the appearance of Eye Lash ra represents the half-RRA.

గుఱ్ఱము guṟṟamu - गुऱ्ऱमु

விற்க viṟka - विऱ्क