Kanagasabapathy Sripavan becomes the first member of the minority community to hold the post in more than two decades.
Narendra Modi has arrived in Sri Lanka’s Jaffna province, becoming the first Indian premier to visit the region in almost 30 years.
Saturday’s trip to the province where the Liberation Tigers of Tamil Eelam (LTTE) waged a decades-long bloody campaign against the government is part of an effort to promote peace and greater autonomy.
Modi is expected to hand over at least 27,000 new homes in Jaffna to mostly ethnic Tamils who became homeless during the civil war.
His brief visit is seen as hugely symbolic, particularly after he called on the majority-Sinhalese government on Friday to fully implement a 1987 constitutional provision on greater autonomy.
Jaffna is the former stronghold of the Tamil Tigers who were defeated six years ago.
Al Jazeera’s Minelle Fernandez, reporting from Jaffna, said that the visit is “a very important dynamic within the relationship” between India and Sri Lanka.
Our correspondent said that Modi is set to meet with Tamil leaders to discuss how to speed up the reconciliation process.
“Sri Lanka has lived through decades of tragic violence and conflict,” Modi said on Friday, referring to 37-years of ethnic war which killed at least 100,000 people, mostly Tamils.
While reconstruction has begun in some parts of Jaffna city, many neighbourhoods and surrounding villages are still strewn with rubble as a legacy of the heavy bombardments that they endured over the decades.
Modi told the Sinhalese-dominated parliament in Colombo that “cooperative federalism” was working well in India and suggested it could be a model for Sri Lanka too.
A Tamil council was elected in September 2013, five years after the war ended, but it lacks legislative authority.
India has long supported greater autonomy for the minority group, but Suresh Premachandran, a Tamil lawmaker from Jaffna, said Modi’s comments were the strongest in a long time.
“He is going to be very welcome after the powerful message he sent,” Premachandran told the AFP news agency.
Sri Lanka’s new president, Maithripala Sirisena, came to power in January promising ethnic reconciliation and accountability for alleged war crimes committed by security forces under the command of former leader Mahinda Rajapakse.
Tens of thousands of troops are still garrisoned in Jaffna despite international calls for a scaling-back of numbers, although there were few soldiers in evidence there ahead of Modi’s visit.
On his way to Jaffna Modi will stop at the north-western town of Talaimannar, the closest point to India, to flag off a train service restored after decades of war.
Indian loans have already helped restore rail services to Jaffna, 400-km north of Colombo, and Modi has pledged $318 million to rehabilitate Sri Lanka’s dilapidated railway network.