It sounds like you’re looking for a Tamil keyboard layout that supports the MCL (Muthulakshmi / Modified Tamil Keyboard) style — specifically the Mangai font variant — along with a TTF font file and the associated keyboard input method.
Example:
| Key | Output | | :--- | :--- | | 1 | ௧ (Tamil 1) | | 2 | ௨ (Tamil 2) | | 3 | ௩ (Tamil 3) | | 4 | ௪ (Tamil 4) | | 5 | ௫ (Tamil 5) | | 6 | ௬ (Tamil 6) | | 7 | ௭ (Tamil 7) | | 8 | ௮ (Tamil 8) | | 9 | ௯ (Tamil 9) | | 0 | ௦ (Tamil 0) | mcl mangai tamil font keyboard layout ttf
Install: Right-click the .ttf file and select Install, or drag it into the C:\Windows\Fonts folder. It sounds like you’re looking for a Tamil