Unfortunately you don't provide a lot of details about the font in question (nor a link where to download the specific variant you are trying to use: there seem to many variants of 'Kruti Dev' around, AFAICT based on a quick web search, and for others not familiar with Hindi fonts or Devanagari script it's rather difficult to test given the lack of information).
Nevertheless, based on the font names I saw while
searching for a suitable font to download and test, I guess that you hit a known issue with Inkscape: Probably the actual name of the font you installed is '
Kruti Dev 020', but Inkscape drops the leading zero from the substring '020' and thus looks for a font named '
Kruti Dev 20' (and fails to find it because there is no such font installed).
Related bug reports: