One of the many things I learned from the book An Early History of Vaiśālī was about the Ñātika clan. They were perhaps the second-most important of the clans that made up the Vajjian Leagure (after the Licchavīs), yet there is little information about them, and they seem almost absent from the Pali texts.
One of the rather noteworthy aspects of the clan is how variable the spelling of their name is. We find Jṇātṛika or Jṇātaka in Sanskrit; Ñātaka in Pali, Nāyika in Jain Prakrit, and well as Nāṭaka, and so on. The variety of forms and dialectical variations is forbidding, but it appears that the sense of the word is simply “the clan”, i.e. it is ñāti as in “family”.
By far the most famous member of the clan was Mahāvīra, the leader of the Jains. In Pali, he is known as Nigaṇṭha Nāṭaputta. The later name is explained by the commentary as “son of a dancer”; it is also sometimes spelled Nāthaputta (son of a lord). However given the universal Jain tradition that he was a Jṇātṛika, it seems certain that this is a misunderstanding, and that Nāṭaputta in fact means “a son of the Jṇātṛi clan”, i.e. a Jṇātṛika. It is the same pattern as Sākyaputta, which means “Sakyan”.
Given this, perhaps we should reconsider how we present his name. Nigaṇṭha means “knotless”, but it is just a term for a Jain ascetic (as bhikkhu is for Buddhists). Perhaps we should translate his name as “the Jain monk of the Ñātika clan”. @Brahmali
But it appears that this is not the only relic of the Ñātikas that is obscured by spelling. There is a town called Nādika, Nātika, Ñātika, etc., which lay on the road between Kotigama (near the Ganges crossing from Pataligama) and Vesali. The Buddha visits there on a number of occasions.
The commentary explains the name in two different ways. The DN commentary relates it to ñāti as in family, whereas the SN commentary calls it nādika from a pond (nadi = “river”). It would seem that this old confusion in spelling led to the effective disappearance of the clan from Buddhist memory.
This being so, we should accept the first derivation, and regard Ñātikā as the correct spelling.
Notably the texts never say Ñātikagāma “the village of the Ñātikas”. Normally we find the singular form, often in accusative (nātike). And the Buddha is said to “enter Ñātika for alms”, so clearly it was a town or village. It seems this may be a reason why it has been taken simply as the name of the place rather than of the people. However in DN 16 the Buddha is said to go to Ñātikā (in plural). In Pali, a region is often named in plural after the people who live there, such as kosalesu “among the Kosalans", or “in the land of the Kosalans”. Thus Ñātikā would mean “the land of the Ñātikas”.
There is currently only very vague information as to where the Nāyikas/Ñātikas/Jṇātṛikas lived.
They are said to have had their main seats in Kuṇḍapura and Kollāga, which were suburbs of Vesali. Maps typically show them to the north-east of Vesali. Ñātika is south of Vesali, but of course it is more than likely that a large clan lived in several places.