Palani is a town and holy location (tirtha) in Tamil Nadu's
eastern region, some 60 miles northwest of Madurai.
Palani is one of six temples devoted to Murugan in Tamil
Nadu.
Murugan is a hill deity who has been absorbed into the
greater pantheon as a version of the god Skanda, Shiva's son.
Five of these temples have been reliably identified, and
each is linked to a certain place, ecology, and event in Murugan's legendary
career—in the instance of Palani, Murugan spent time there as a young monk.
In Tamil Nadu, every other shrine to Murugan might be
regarded the sixth of these temples.
Murugan's worship is therefore a symbol of Tamil pride and
identity, and since the number six connotes completeness—as in the six
directions or the six chakras in the subtle body—it also implies that nothing
more is required.
See Fred Clothey's article "Pilgrimage Centers in the
Tamil Cultus of Murukan" in Journal of the American Academy of Religion,
Vol. 40, No. 1 for more details (1972).