Church records
India had no civil registration (including as birth certificates) as such. The next best thing for a genealogist is to use Church Records. About 80% of all baptism, marriage and burial records have survived today, and the good news is that they are all indexed and available on microfilm. Records of baptisms, marriages and burials are available 1698-1968, and are housed in the OIOC in London. If you live outside London, then the best way to have access to these records is to use the LDS (Mormon) microfilms, which will be available in an LDS Family History Centre near you. For details on how to use the OIOC records on microfilm, some transcriptions, addresses and photos of churches in India, visit the webpage on Church Records.
Some regiments of the British Army (not the HEIC Army) chose to have their records included in the General Registrar's Office records at what was formerly called St Catherine's House, in London. If your ancestor was in the British Army and you are unable to find your ancestor's baptism record in the church records held at the OIOC or on microfilm, there is a chance that they will be available in the Army Ecclesiastical Returns of the General Registrar's Office. Indexes to these records are available in most genealogical libraries and family history societies.