First of all you can buy constructed house if you had invested/deposited amount in capital gain bank account which is for construction of house.
Secondly if you get a constructed house directly which means you are directly purchasing the house in this case 2 year limit will be applicable which has expired.
What is asbestor house sheet?
I am assuming that you are saying that you would purchase a land and get a house constructed for 1 lakh to save tax, I guess you can do that and save tax that's the only option you have now if you had sold a land then you need to invest entire sale consideration and not only capital gain amount to save capital gain tax.
If you can't claim any exemption then you need to pay atleast 5 lakh tax i.e. 25 lakh * 20% + education cess.
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