Tamil Brahmi inscriptions have been found on cave entrances, stone beds, potsherds, jar burials, coins,[5] seals, and rings.

According to Mahadevan, in the earliest stages of the script the inherent vowel was either abandoned, as above, or the bare consonant was ambiguous as to whether it implied a short a or not.

[10] Similarly, the tenth chapter of the Lalitavistara, named Lipisala samdarshana parivarta, lists Dravida-lipi and Dakshinya-lipi as two of sixty four scripts that Siddhartha (later the Gautam Buddha) learnt as a child from his gurus in Vedic schools, a list that is found in both Indian Buddhist texts and its ancient Chinese translations.

[14] According to Falk these supposed inscriptions are not Brahmi letters, but misinterpreted non-linguistic Megalithic graffiti symbols, which were used in South India during the pre-literate era.

[18] These developments transformed the oral bardic Tamil literary culture to the written Sangam literature in the centuries that followed.

[18] Since the 1990s, pre-Ashokan dates have been proposed based on excavations and discoveries of graphite covered ancient remains in Sri Lanka.

[20][21] The findings of Coningham et al based on the carbon dating of excavated potsherds led to the proposal that the Sri Lankan Brahmi developed before Ashokan era, at least by the 5th to 4th century BCE, from where it came to Tamil region evolving into the Tamil Brahmi, and thereafter spread across South Asia due to trade networks.

First, states Falk, the Coningham team has admitted later that they did not use the carbon dating correction necessary for the Southern hemisphere and used the calibration curves for north Pakistan.

[24] Between 2011 and 2013, for example, Rajan and Yatheeskumar published their findings from excavations at Porunthal and Kodumanal in Tamil Nadu, where numerous graffiti and inscription fragments on archaeological pieces have been unearthed.

Some of the earliest supposed inscriptions are not Brahmi letters at all, but merely misinterpreted Megalithic graffiti symbols, which were used in South India for several centuries during the pre-literate era.

Falk considers these reports as "regional chauvinism" just like the Sri Lankan claims of their island being the origin of a Brahmi script from which the Tamil-Brahmi developed.

[26] Linguist David Shulman concurs that there are reasons to be skeptical of pre-Ashokan dates for Tamil-Brahmi, but recommends that one should keep an open mind.

Both seem to use similar letters to indicate phonemes that are unique to Dravidian languages although Sinhala-Brahmi was used to write an Indo-Aryan Prakrit used in the island of Sri Lanka possibly from ongoing maritime relationship with Gujarat and other parts of India.

[32] According to Gift Siromony, the types of Tamil Brahmi writings do not follow a very clear chronology and can lead to confusion in dating.

[36] According to Zvelebil, its origins likely were with the Jains and the Buddhists, but it was soon understood and used by kings, chiefs, potters and other common people from a variety of backgrounds.

[38][39] Cave and rock bed Tamil Brahmi inscriptions, as well as those found near Madurai, are typically donatory and dedicated resting places and resources for monks.

Other major usages of Tamil Brahmi inscriptions are similar to those found in Andhra Pradesh, such as in coins and those that mention merchants and traders of gold, sugar, iron, salt and textiles.

[41] A significant archaeological source of Tamil Brahmi inscriptions has been the region between Palghat gap and Coimbatore along the Kaveri river and to its delta.

A similar mix of Tamil Brahmi and Brahmi script is found in shards, potsherds and rock inscriptions all along the coast of the Bay of Bengal, from Salihundam in northeast Andhra Pradesh to ancient near-coast settlements of Tamil Nadu such as those near Vaddamanu, Amaravati, Arikamedu, Kanchipuram, Vallam, Alagankulam and Korkai.

[46] A. C. Burnell (1874), attempted the earliest work on South Indian paleography, but it was due to the efforts of K. V. Subrahmanya Aiyar (1924), H. Krishna Sastri and K. K. Pillay that it was understood to be written in an early form of Tamil, not Prakrit.