Sub-lease on expired lease plot

I am planning to buy a newly constructed portion in nazimabad, karachi. The portion is built on a residential plot. The lease for the plot was expired in 1998 and the builder has applied for the extension in june 2020.
I want to ask that should i buy this portion? The builder is saying that he will provide sub-lease of the portion. How could this sub-lease can be provided if actual lease is not yet extended?

Ahsan bro,

This forum is dominated by Islamabadi investors who are completely unaware that in Karachi you can co-own a house in portions.

Though, this option would have been ideal for Islamabad, where property is super expensive and almost all houses 200 yards and above are occupied in separate portions.

So we need more active participation of Karachiites, unless they have other forum to discuss on.