Solution: Some modern versions of Word aggressively convert text to Unicode. Use Notepad (on Windows) or WordPad first, then copy-paste into Word while preserving source formatting.
Once you have the .ttf (TrueType Font) or .otf file for MCL Kannamai, follow these steps: mcl kannamai tamil font
A note on copyright: MCL originally held copyright over this font. However, given its age and abandonment, many users treat it as abandonware. For commercial projects, it is best to use a modern alternative unless you own a license. Solution: Some modern versions of Word aggressively convert