In his condolence message Kumar described Patnaik as a popular leader and prominent social worker, according to an official statement.
Patnaik had played a prominent role in development of Odisha and he would be remembered for long as "pillar of Odisha politics," Kumar said.
The Bihar chief minister prayed for strength to Patnaik's family to bear the loss.
The veteran Odisha leader died at a hospital early today following a cardiac arrest, few hours after he offered prayers at Lord Venkateswara temple at Tirumala in Tirupati.