There is no such thing as caste in Dravidian Aaiyyanism. Let me repeat this. There is no concept of caste in Aaiyyanism. We are all one.
Many Dravidian Historians believe that the caste system was introduced by force during the Aryan invasions of the original Dravidian lands, and was forced upon the population to separate us from Oneness and Brahman consciousness. The history of Dravidian Aaiyyanism starts 100,000 years ago when Murugan first appeared and taught humanity how to open the gateways to reach his consciousness and Brahman's via the sacred inscriptions and the language of Dravidian Aaiyyani. For tens of thousands of years humans were living as one until the Kalaiyyan incident (15,000 BC) which destroyed the Aaiyyanist Kingdoms of old.
Aaiyyanism remained in place and was continued by the small community of Dravidian Aaiyyanists who kept the traditions, rituals, and knowledge alive until around 1500BC (3500 years ago). This was when Guru Dattatriya met Swami Aaiyyan (the incarnation of Murugan) and thus the modern and ancient form of Aaiyyanism was disseminated across the world. This was also during the time of the Aryan invasion which brought about the caste system and the pollution of the original Dravidian ideas.
This pollution of philosophy and thought continue to this day where new oppressive laws that were introduced by the Victorian British (such as laws on homosexuality and the laws against the equality of women and the transgender community) were readily accepted by the corrupted form of Aryan Hindus as their philosophy was already soiled.
Most, if not all Aaiyyanists do not believe in the oppressive, unjust, caste system, or the patriarchy and xenophobia of the northern Hindu tradition, that is made real by modern groups such as the BJP. The most revered Dravidian Aaiyyanists Teachers and Gurus have been women and indigenous peoples (such as Guru Dravida Karnataka). An indigenous person to the Northern invaders were classed as untouchables, according to their oppressive caste system rules, as the indigenous people of South India were following the true teachings of Brahman.
Let us be clear. The northern invaders did take many aspects of thought and philosophy from the Dravidian peoples that would later become part of mainstream Hinduism - such as the concept of Brahman, Murugan, reincarnation, the age and structure of the Universe etc... But they added their own politics and control systems to subjugate the population and keep them in their place. The caste system was one such invention.
Thus all Dravidian Aaiyyanists reject all notions of caste and do freely marry, cohabit, befriend all peoples regardless of their caste, origin, race or gender.