... I don't think you will find this information in the Census book. I think the copy [below] was at the intervention of the National Spiritual Assembly of the Bahá'ís of India and they procured it from the Census department by making some efforts.
However, I must add these figures do not reflect the true picture of the statistics of the Bahá'í community in India for various reasons. Bahá'í is included in the others category in the column of religion and many enumerators don't know about the Faith, or they tend to write religion as per the name of the person.
In the next census, that is in 2001, I think the number had doubled or so, though that is no indication of the true Bahá'í population. I am not aware of the results of the 2011 census. The Bahá'í Community is therefore engaged in entering the data with regard to the Bahá'ís of India and elsewhere though a statistical programme, though there are teething problems in doing so. ... (Chandigarh, 08-03-14)