Which area should be mentioned in the sale deed

Hello,

This about the registration of a new flat that was under construction in MP. The builder has mentioned built-up area in the Sale Deed where as the buyer has paid money on the basis of super built-up. I have the following questions to seek advise from the community.

1. If the property is registered on the built-up area, the value of the property will come down in case of second sale. How can the buyer protect his/her interest?

2. Is there any state law that prohibits builder from mentioning super built-up?

3. Can the buyer insist on mentioning of super-built up in the Sale Deed?

Thanks