JD(U) president Nitish Kumar's decision to join the NDA is correct and taken at the right time for the development of Bihar, BJP ally and Republican Party of India (A) chief Ramdas Athawale said on Monday. Kumar took oath as the chief minister of Bihar for a record ninth time on Sunday after a dramatic volteface, ditching the 'Mahagathbandhan' and the opposition INDIA bloc, and forming a new government with the BJP, which he had dumped less than 18 months ago. Talking to PTI, Athawale said the opposition terming Kumar as "Paltu Ram" (one who switches sides) is not justified. "Nitish Kumar's decision is correct and he has taken it at the right time for the development of Bihar. This is a challenge to the Congress," he said. "He has joined the NDA to work under the leadership of Prime Minister Narendra Modi. We all welcome him," the RPI (A) chief said. On the opposition calling Kumar an opportunist, Athawale said, "He is not an opportunist but the Congress is." Kumar on Sunday had .