This character is a Other Letter and is mainly used in the Arabic script.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it is written as Arabic letter from right to left. When changing direction it is not mirrored. The word that U+067A forms with similar adjacent characters prevents a line break inside it. The glyph can be confused with 4 other glyphs.
The Wikipedia has the following information about this codepoint:
Ṭhē is an additional letter of the Arabic script. It has the basic shape of tāʼ (ت), but with vertical dots, rather than horizontal. It is not used in the Arabic alphabet itself, but is used to represent an aspirated [ʈʰ] in Sindhi, a language mainly spoken in Pakistan. Its Latin description is ṭh, or sometimes t́h.
In an older version of the script, the ٽ was used instead of ٺ and vice versa.
Sindhi is also written in Devanagari, where the corresponding letter is ठ.
The letter is encoded in the Arabic Unicode block as Tteheh at U+067A.