The change of title of Nagvanshi kings from Rai to Karna may be due to victory over or alliance with descendant of Lakshmikarna of Kalachuri dynasty.
According to Nag Vanshavali, Bhim Karna had to fight with Haihaiyavansi Raksel of Surguja.
But Bhim Karna defeated the Raksel and captured territory up to Barwe and Palamu.
The change of title from Rai to Karn may be due to his victory over or alliance with descendants of Lakshmikarna the king of Kalachuris of Tripuri.
[2] In 2009, At Khukhragarh from excavation, archaeological department found the remains of the Nagvanshi dynasty's fort, an ancient Shiva temple complex, coins and pottery dating back to 12th century AD.