Tamil Unicode fonts not displaying proper

Please advise why Tamil Unicode fonts are not displaying proper within Unity.

3089994–232980–UnicodeFonts-IlaSundaram-Set1.zip (527 KB)

I’m not a expert in Tamil but it tested the first font of the set and it seems to display the Tamil it gave it properly.
What version of unity you are using with what font and what text?
Are you using the normal unity text or TextMeshPro?