What is BDA Khata?

[satsaa]

Hi,

I bought a site recently which has BBMP B Khata and the site in a BDA approved layout.

Now I approached an agent to get BBMP A Khata for the same. He says we need to get BDA Khata & then BBMP A Khata. Am not able to find details around BDA Khata anywhere. Is it necessary to get BDA Khata, if so for what purpose? Can we get directly BBMP A Khata without BDA Khata?

Please suggest.