There 3 sangams but the literary of 2 sangams survived. 1st sangam works were lost
Sangam iterature only covers the 2nd sangam's tolkapiyam. And 3rd sangam's 18 ethical and epics. Attached link should be of help. Your copper plate inscription is a dubious brahmin's forgery.
Early Tamil literature (1st–10th century)
Śaṅgam literature
Early classical Tamil literature is represented by eight anthologies of lyrics, 10 long poems, and a grammar called the
Tolkāppiyam (“Old Composition”). According to a fanciful Tamil tradition, this literature was produced by poets of three “academies,” or
śaṅgams, that in the hoary past were centred in the southern Indian city of Madurai and supposedly lasted 4,400, 3,700, and 1,850 years, respectively.
The Tolkāppiyam was ascribed to the second śaṅgam, the eight anthologies and 10 long poems to the third; according to tradition, nothing is
extant from the first
śaṅgam. The early literature, itself known as Saṅgam,
comprises 2,381 poems, ranging from four to nearly 800 lines each and assigned to 473 poets who are known by name or epithet; about 100 poems are anonymous. Though the literature does not go back as far as native tradition would have it, it is generally ascribed to the first three centuries of the Christian Era and represents the oldest non-Sanskrit literature to be found on the South Asian subcontinent.
The eight anthologies and their contents, excluding opening invocations that were added later, are as follows:
akam anthologies consisting of (1)
Kuṟuntokai, 400 love poems, (2)
Naṟṟiṇai, 400 love poems, (3)
Akanāṉūṟu, 400 love poems, (4)
Aiṅkuṟunūṟu, 500 love poems, each 100 (assigned to a different poet) dealing with one of five phases of love, (5)
Kalittokai, 150 love poems in a metre called
kali; and
puṟam anthologies consisting of (6)
Puṟanāṉūṟu, 400 poems, (7)
Patiṟṟuppattu (“The Ten Tens”), 100 poems on kings (the first and last decades are missing), and (8)
Paripāṭal, a collection of 70 religious poems.
Paripāṭal and
Kalittokai appear to be the latest of the anthologies;
Kuṟuntokai and
Puṟanāṉūṟu probably contain the earliest
compositions. The remarkable work of grammar and
rhetoric,
Tolkāppiyam, is the crucial text for an understanding of early
Tamil language and literature. Divided into three sections (each consisting of
cūttirams, or aphorisms)—sounds, words, and meaning—the
Tolkāppiyam details, in the third, the canons of Śaṅgam poetic traditions.
Eighteen Ethical Works (3rd sangam)
- Ainkurunuru (composed by Gudalur Mar)
- Ahanuru (compiled by Rudrasarman)
Pattuppattu
It consists of the following works:
- Murugatrupadai (composed by Nakkirar)
Epics
Cilappatikāram (“The Jewelled Anklet”)
Maṇimēkalai (“The Girdle of Gems”) and including an incomplete narrative,
Peruṅkatai (“The Great Story”), the
Cīvakacintāmaṇi (“The Amulet of Cīvakaṉ”) by Tiruttakkatēvar, and
Cūḷāmaṇĭ (“The Crest Jewel”) by Tōlāmoḻittēvar.
https://www.britannica.com/art/South-Asian-arts/Dravidian-literature-1st-19th-century
