property tax

Yes, if you purchase/construct new house property from the capital gains received by you, from the sell of property worth 80 lakhs......... you can save on long term capital gains tax u/s. 54 of IT act, provided the old property was held for 2 years or more. (As of now long term capital gain is taxed at 20.6% with cess)

Auround 10 to 20% of the tax has to be paid.