The government has said that at least 15,000 LTTE fighters died in the conflict, but these figures are yet to be confirmed.
According to UN estimates, up to 100,000 people died in the 26 years of fighting.
The government has been criticised for its handling of the conflict, for the treatment of internally displaced people and for preventing aid groups access to the conflict zone.
It said on Friday that the 280,000 Tamil civilians who fled the fighting and who are now being held in camps will be rehoused within six months.
The pledge was made after Mahinda Rajapaksa, the Sri Lankan president, met two envoys from India to discuss the situation and aid.
India has promised $20m in aid and is expected to give another $105m for reconstruction and resettlement.
Rajapaksa also promised to give a copy of the LTTE leader's death certificate to Indian authorities. Velupillai Prabhakaran was wanted over the assassination of Rajiv Gandhi, a former Indian prime minister.
The two countries have agreed to provide humanitarian relief to the displaced Tamils, describing the need as "urgent". Many left the conflict zone in a poor state of health and were malnourished.
"The government of Sri Lanka ... outlined a 180-day plan to resettle the bulk of IDPs [internally displaced persons] to their original places of habitation," they said in a joint statement.
The Indian government is "committed to provide all possible assistance in the implementation of such a plan in areas such as de-mining, provision of civil infrastructure and reconstruction of houses", the statement said.
Residents of the capital, Colombo, are expected to march to parliament later on Friday in support of the government's victory.
The rally is expected to coincide with a visit by Ban Ki-moon, the UN secretary-general, who is arriving in the country on a 24-hour mission to press the government for unfettered humanitarian access to the former conflict zone.
Ban has described the situation in Sri Lanka and the plight of those forced out of their homes as of "grave and growing concern".
The high-profile visit comes as UN and relief aid groups complain their access to the displaced camps - which the government calls "welfare villages" - has been restricted.
The Tigers had said the government planned to hold the displaced there indefinitely in what it dubbed "concentration camps".
The government says remaining pockets of Tamil Tiger fighters need to be removed and infrastructure rebuilt before civilians can return.'Lasting peace'
"[I lived] near Pudukuripu, in a place called Padapalaayam ... Every hour the Sri Lankan army fired 400 to 500 shells. We were forced to live inside the bunkers.
"My elder brother was injured in the shelling and he was taken to the hospital ... To remain alive and avoid all the atrocities I escaped to India.
"I escaped to India by boat, travelling with many unknown people."
Pradeepan, Tamil refugee
Nimmi Gowrinathan, the director of South Asia Programmes for Operation USA in New York, an international relief organisation, told Al Jazeera: "If past visits by UN officials have been any sort of record I don't think [Ban] is going to achieve what we need him to achieve at this stage for the humanitarian crisis.
"The Tamil people are hesitant to believe there is the political will to provide aid services," she said.
Ban has also made it clear that he wants to see swift progress not only on immediate humanitarian aid and reconstruction, but also on reconciliation with the Tamil minority, which make up 12.6 per cent of Sri Lanka's population of 20 million.
"Progress on all three fronts must be in parallel, and it must begin now," Ban has said, adding that any serious allegations of war crimes "should be properly investigated".
On Monday, the president declared the country "liberated" from the separatist fighters after the last pocket of territory held by them was taken.