If sale of a portion of property then how to calculate coa

what do you mean say by portion of property.  Can you please elaborate it a bit so as to have some understanding of the case.

sir

i mean if i sale today 5% portion for rs 2 lac of a land from front side or back side & COA is rs 5 lac for full plot in 2007 .then what will be the COA for saled plot & LTCG?

dear sir

     as above.

thanks