House Acquisition Cost for capital gains purpose

I have bought a plot in bangalore and constructed house in 2003. Now I am planning to sell the property.

For calculating Capital gains, for land I have government value in a registered document.

I am looking at how to arrive at my acquisition cost of the building.

Will approved evaluator report of cost of building at time of acquisition is accepted by income tax?

I don't have any bills for the house constructed.

Thanks