to install an old orthography Malayalam Unicode font which is required to read the posts below]
The symbol
is used as Malayalam version of Devanagiri Avagraha (U+093D). It is called Praslesham (പ്രശ്ലേഷം) in Malayalam. This is a punctuation simillar in meaning to '-' (hyphon). If the shape of U+093D is same as that of Praslesham, then we don't need to encode it for Malayalam; just like other punctuations - comma, period etc. But, typical shape of U+093D is not what is used in Malayalam. Devanagiri shape could potentially conflict with Malayalam ട (U+0D1F).