The Sri Lankan Tamils are concentrated in the North and East regions of Sri Lanka. This can be explained as follows:

Historical Background:
• Sri Lanka has a long history of ethnic conflict between the majority Sinhalese and minority Tamils.
• The Tamils are believed to have migrated to Sri Lanka from southern India in the 10th century AD.
• The Tamils were initially concentrated in the Jaffna peninsula in the Northern Province and the Eastern Province of Sri Lanka.

Geographical Distribution:
• The Northern Province and the Eastern Province of Sri Lanka are the traditional homeland of the Sri Lankan Tamils.
• The Northern Province comprises the districts of Jaffna, Kilinochchi, Mannar, Mullaitivu, and Vavuniya.
• The Eastern Province comprises the districts of Trincomalee, Batticaloa, and Ampara.
• The Northern Province and the Eastern Province together make up about one-third of the land area of Sri Lanka.

Political Situation:
• The Sri Lankan Tamils have faced discrimination and marginalization by successive Sinhalese-dominated governments.
• The Tamils have demanded greater autonomy and self-determination, which has been opposed by the Sri Lankan government.
• The conflict between the Sri Lankan government and the Tamil rebels intensified in the 1980s and 1990s, leading to a brutal civil war that lasted for over 25 years.
• The civil war ended in 2009, with the Sri Lankan government defeating the Tamil rebels.
• The Northern Province and the Eastern Province remain politically and economically marginalized, despite the end of the civil war.

Conclusion:
In conclusion, the Sri Lankan Tamils are concentrated in the Northern and Eastern Provinces of Sri Lanka, which is their traditional homeland. The Tamils have faced discrimination and marginalization by the Sri Lankan government, leading to a long and brutal civil war. The Northern and Eastern Provinces remain politically and economically marginalized, despite the end of the civil war.