This section is from the book "Some Contributions Of South India To Indian Culture", by S. Krishnaswami Aiyangar. Also available from Amazon: Some Contributions of South India to Indian Culture.
This political southern limit of Asoka's empire marks also the limits of active Buddhist propaganda reflected in the last sentence quoted above from rock edict XIII. The meaning of this statement in the edict is that while people in the neighbouring kingdoms followed the teachings of the Buddha of their own motion the active propagation of the gospel that he actually organised stopped short of this limit. This inference is confirmed by what we find detailed in the Mahavamsa of Ceylon. Referring to the missions for the propagation of the faith sent to various localities for the purpose of spreading the teachings of "the enlightened one " the Mahavamsa has the following passage: "When the thera Moggaliputta, the illuminator of the religion of the conqueror had brought the (third) council to an end and when, looking into the future, he had beheld the founding of the religion in adjacent countries, (then) in the month of Kattika he sent forth theras, one here and one there. The thera Majjhantika he sent to Kasmira and Gandhara, the thera Mahadeva he sent to Mahisamandala. To Vana-vasa he sent the thera named Rakkhita, and to Aparantaka the Yona named Dhammarakkhita, but the thera Maharakkhita he sent into the country of the Yona. He sent the thera Maj-jhima to the Himalaya country, and to Suvanna-bhumi he sent the two theras Sona and Uttara. The great thera Mahinda, the theras Itthiya, Uttiya, Sambala and Bhaddhasala his disciples, these five theras he sent forth with the charge: "Ye shall found in the lovely island of Lanka the lovely religion of the Conqueror."
In this recital the places referable to the country south of the Vindhyas stopped short at Vanavasa, all the other places being obviously north of Vanavasa with the doubtful exception of Mahisamandala. This was hitherto identified with what is now the state of Mysore, but from Tamil literature we find the present state of Mysore occupied altogether otherwise, though undoubtedly one frontier chieftain of Kudanadu (western hill country) was known by the name Erumai (Sans. Mahisa) and apparently gave the name to the country in the following generations. It could hardly be regarded as the country to which Asoka's mission was sent as it is doubtful if it was known by that name in the days of Asoka. Mahismati the capital city of the Mahisakas has satisfactorily been identified with Mandhata on the Narbada round which there were a tribe of people called Mahimsakas. The Mahismandala of Asoka's mission has to be referred to that district. Hence Vanavasa,
Banavase in Dharwar the capital of the division of Banavase 12,000 was the southernmost limit of the missionary activity of Asoka.
The great centres of Buddhist activity get enumerated in another context in the Mahavamsa. The Ceylon ruler Duttagamani Abhaya held a great congregation on the occasion of laying the foundation stone of the Great Stupa (Maha Vihara) that he constructed. To this congregation he invited the priestly communities from the various well-known Buddhist centres. This invitation was responded to by brethren of the holy order in as many as fourteen centres, the centres being: - Bajagrha, the ancient capital of Magadha, Is'itapatana, the deer park in Benares, Jetarama-Vihara in Sravasti in Nepal-Tarai, Mahavana in Vaisali (North Bengal), Ghositarama in Kausambi not far from Allahabad, Dakkhinagiri-Vihara in Ujjain in Malva, Asokarama in Pupphapura (Pataliputra or Patna), Kasmir, Pallava-bhogga, probably somewhere in the region of the Indus, Alasanda of the Yonas, probably the Alexandria represented by the modern Uch in the north of Sindh, "the road through the Vindhyan forest mountains" possibly the centre Mahismati of the Mahlsa-mandala, Bodhimanda-vihara (Bodh-Gaya), the Vanavasa country and lastly the great Kelasa-vihara." This Kailasa-vihara may refer to Ama-ravati in the Guntur district while it is barely possible it may refer to Ellora in the Nizam's dominions; but the trend of the description would indicate the former rather than the latter. This detailed list of Buddhist centres excludes the Tamil country altogether. Whether the representatives actually came or no is a different matter. But these were centres of holy reputation at the time in the estimation of the author. He apparently had recourse to older chronicles kept in the Mahavihara, the construction of which is under discussion. If the Tamil country did contain any vihara of similar reputation it is not likely that that would be omitted in the narration. Hence the inference seems quite warranted that active Buddhist propaganda stop ped short of the Tamil land both in the days of Asoka and in the centuries following almost to the middle of the century before Christ. Remembering that there was nothing to prevent individual Buddhists, or even bodies of them, following the bent of their mind in matters of religion even in the Tamil country, it is clear that the active propaganda under the imperial impulse of Asoka might still have stopped short of the Tamil country. That seems the state of things in respect of Buddhism reflected in this body of Tamil literature referring to the times under discussion.