Mukta is a Unicode compliant, contemporary, mono-linear font family available in seven weights, supporting Devanagari, Gujarati, Gurumukhi, Tamil and Latin scripts.
Looks like it is a problem with any OpenType font on OS X (I am using 10.9.5). I tried ITF Devanagari on the font’s web site, and it exhibits similar issues. Please feel free to close the issue.
This is probably not related to the font, but I wanted to flag it just in case.
In some places (as seen in screenshot below), adding a dotted consonant messes up all further layout in the line. I am using TextEdit on Mac.