From the Wikipedia page 
The National Archives of India (NAI) is a repository of the non-current records of the Government of India and is holding them in trust for the use of administrators and scholars. Originally established as the 'Imperial Record Department' in 1891, in Calcutta, then capital of British India. NAI is today situated at the Inter-section of Janpath and Rajpath, in Delhi, and functions as an attached Office of the Department of Culture under Ministry of Culture, Government of India.
It was set up in 11 March 1891 in Calcutta (Kolkata) as the 'Imperial Record Department' and was subsequently transferred to the new Capital, New Delhi, in 1911 and it was shifted to its present building in 1926. Built in late neo-classical style, it was in fact one of four museums and archives building planned by Edwin Lutyens at the interaction of King's way and Queen's way, known as 'Point B', however only this one was actually built.
Shri K.R. Narayanan, then President of India, declared open the "Museum of the National Archives" to the general public on 6 July 1998. This Museum is a representative overview of the multifarious holdings of the National Archives, promotes a common man's interest in archival holdings.
It has a Regional Office at Bhopal and three Record Centres at Bhubaneswar, Jaipur and Pondicherry.
The records holdings in the National Archives are in a regular series starting from the year 1748 A.D. These are in English, Arabic, Hindi, Persian, Sanskrit, Modi, Urdu etc., These records are on paper, palm leaf, birch bark, parchment etc. They are broadly of four categories : Public Records, Oriental Records, Manuscripts and Private Papers.