The document was created using a different non-Unicode font. You need to identify the exact font used (e.g., MCL Kannamai Bold, MCL Kannamai Narrow) and re-apply it to the text.
The font was named after Kannamai, a legendary calligrapher from his village who could make letters dance with a single stroke of her reed pen. When the world moved to screens, Elango spent months meticulously digitizing her handwriting, ensuring every curve of the 'அ' and every loop of the 'க' captured her spirited personality. mcl kannamai tamil font
No, it is generally not freeware. It is a commercial legacy font. However, some enthusiasts have released "clones" under different names—approach those with skepticism. The document was created using a different non-Unicode font