Senior Gujarat-cadre forest service officer Bharat Lal will be joint secretary to Mr Kovind, said an order issued today by the Department of Personnel and Training (DoPT).
The Appointments Committee of the Cabinet, headed by Prime Minister Narendra Modi, approved these appointments for an initial period of two years, it said.
Mr Kothari, a 1978-batch IAS officer of Haryana cadre, retired in June last year as DoPT secretary. He was in November 2016 appointed as the chief of the government's head-hunting agency, the PESB.
Mr Kothari has served in various positions both at the Centre and state cadre.
Mr Malik is at present Distinguished Fellow at Observer Research Foundation (ORF), a policy think tank. He is head of the ORF's Neighbourhood Regional Studies Initiative.
A journalist for 20 years, Mr Malik is a columnist for several leading Indian and international publications.
He has co-authored and authored books including 'India: Spirit of Enterprise'. It encapsulates the story of the growth of India's leading private sector industries since 1991, and its role in the Indian economy, as per his profile on the ORF's website.
Mr Lal, a 1988-batch officer of Indian Forest Service, is at present Resident Commissioner of Gujarat government in Delhi.