Manoj - it may be that the folk you're looking for are part of those who "kept records" by the oral tradition, so unless someone also wrote things down, there may be no records at all. The closer you get to modern times, the more likely there are written records (the Raj and all that, and the English desire to document everything (which is great for us!)).
I got stuck on my person's siblings, and her parents, because the parents would be pre-1900, and the siblings early 1900s. Her baptismal record (in Uttar Pradesh) was difficult enough to find.