Property tax for stilt parking area

[sholla]

I have recently built a duplex GF+2 floors in a 30x40 plot. I have left
the GF fully vacant for parking purpose. In the BBMP tax documentation
there is a clause saying that the tax rate for stilt parking is at 50% of the
normal rate. How does one handle my situation in the online forms ?
All I find is that there is one field labelled "Parking area" for owner (I
ignored the similar field for tenants). Do I just mention the full parking
area sq.ft in this field ? Also do I include this in the built-up area
calculation. Thanks for any pointers..