Combining Bindu Below

It marks a language-specific consonant spelling with a dot below.

A nukta is a mark attached to a consonant to write a sound that a script’s usual letters do not distinguish. This single-dot form is used for some Badaga spellings and in Betta Kurumba and other language orthographies. It belongs inside the word, not as standalone punctuation.

The 2016 proposal requested a single-dot sign for Badaga and related minority-language spelling. In a later Unicode committee record, the originally requested Tamil Sign Nukta is identified as this mark, and the use note expands to Betta Kurumba and other languages.

Is this the same as the two-dot nukta?

No: this is the single-dot form.

The Grantha Sign Nukta, 𑌼, uses two dots; ◌̣ is the generic Combining Dot Below. They are different encoded marks, so neither is a substitute for this language-specific nukta.

Grantha is an older South Indian script historically related to Tamil. Archaic Grantha forms appear on Pallava copper plates from the fifth and sixth centuries CE. Later, Grantha served Sanskrit inscriptions and palm-leaf books of literature and religion; related forms also helped shape Malayalam and writing systems in Southeast Asia.

How do I type combining bindu below?

Insert it after the consonant it modifies.

A keyboard layout must expose the mark. Enter it after its base consonant; without a base, it has nothing to modify. A font or shaping system without support may omit it, show a box, or place it incorrectly.