Society of Genealogists
The Society of Genealogists (SOG) in London has information largely relating to family history in England. However, it also contains an impressive selection of material relating to British India.
Foremost amongst this is the card index of Lt Col H K Percy Smith (1897-1975). The index comprises baptisms, marriages and burials in India. Some of these have been typed into lists by Lt Col Bullock (and others) and are on the open shelves in the Upper Library.
Moreover, some of the church records available at the Society are not found in the N series of India Office Records at the British Library. To see what is available refer to Church records of India at SOG
The shelves in the Upper Library also house a great many books, directories and lists relating to British India. Particularly useful is the open access to the volumes of Bengal Past and Present (although, regrettably, these do not appear to be a complete run).
For details of membership, costs for individual research sessions and opening times, please refer to the SOG website.