The main problem with the infamous Israeli-Apartheid analogy is that discrimination and conflict in Israel is based on religion and not on race. Zionism does not incorporate race theory and does not hold that the Palestinians are racially inferior which was a basic principle of Apartheid and European colonial societies. Its not surprising that Zionists did not adopt such doctrines given that most race theorists regarded the Jews as non-European inferiors. Other problems with the Apartheid analogy are that outside the occupied areas there is full democratic procedure in which Arabs/Moslems also participate and that half of Israeli Jews can reasonably considered to be Arabs.
Sri Lanka is similar to Israel-Palestine in that it is also a religious conflict, between Hindus and Buddhists belonging to separate ethnic groups (Tamils are Hindus and Sinhalese are Buddhists). Although Buddhists outnumber Hindus in Sri Lanka, they are massively outnumbered in neighbouring India, just as the Jews are massively outnumbered by the region's Arab Moslems while forming a majority in Israel. The ability of Tamils to find support, funds and arms in India has fueled the dispute just as the Palestinians have been able to leverage their regional majority to sustain their struggle. The Tamil Tigers who led the Tamil uprising trained in India and negotiations to end the war were often held between India and Sri-Lanka without participation of the Tigers. Until Oslo, Palestinians trained in camps across the Arab world and were not a party to Israeli-Arab negotiations.
Buddhism is a religion with a long history of minority status in India and Sri Lanka is the one place in the Indian sub-continent where it is dominant. Sri Lankan Buddhists have a long history of fighting off Hindu encroachment. This is also similar to Israel, Jews have a long history as a minority everywhere and Israel is the one place where Judaism has been the dominant religion for significant periods. Although they have generally done so passively, Jews have also had to resist encroachment by Islam and Christianity.
The Tamil Tigers were pioneers of suicide bombings, killing both Indian Prime Minister Rajiv Gandhi in 1991 and then the Sri Lankan PM in 1993. In both cases the assassins were suicide bombers, used before the Palestinians adopted this tactic. Unlike the Palestinians, the Tigers managed to liberate territory using military means, but like the Palestinians, they showed complete disregard for the principles of human rights both with regard to their Sinhalese rivals and internally in their management of the Tamil population.
The end of this conflict was one of the symptoms of the emergence of China as a serious world power, the Chinese have a history of conflict with India and although they have abandoned Buddhism (and fight it in Tibet), China was once a mainly Buddhist county and it has played an important role in Chinese history. With Chinese support (and yes, the Israelis were also involved) the Sri Lankan government decisively defeated the Tigers and ended the Tamil uprising. Although thousands of Tamil civilians were killed in the last stages of the war, Sri Lanka faced little international protest.
As an analogy for religious conflict Sri Lanka is a better model for understanding the Palestinian-Israeli conflict then either of the two popular models, Northern Ireland and South Africa and it is perhaps significant that the end of this conflict was the total defeat of the Tamils.
Finally one should remember that while analogies may be useful as models, they are in the end just analogies and not genuine analysis.
The South African analogy is particularly problematic in that there is little resemblance between the ANC, which always sought equal and human rights for all South Africans while Palestinian organizations were frequently anti-Semitic (sometimes virulently) and never even pretended to accept ideals of Human Rights. The similarity of the Palestinians to the Tamils is one of the elements which make Sri Lanka a better model.