Change of Land Use info required

[nagsbhat]

Hi,
Please let me know the process of construction of a commercial building G+2. Site details:
size: 40x60
Front Road: 80 ft. Many commercials buildings are coming up on other block which are 50x80 sites.
Originally allotted for residential purpose by BDA.
Currently under BBMP. Plan sanctioning authority is BBMP.
One broker (involved in plan approval) told me that 20% can be constructed as commercial and rest has to be residential. Another person is suggesting to go for change of land use from BDA to build 100% commercial building. Yet another person is telling 100% can be constructed without change of Land use from BDA if the 80ft road is declared commercial (not sure how to know)

Help will be much appreciated.

Regards,
Nag