capital gain exemption u/s 54.

If the asset is sold in the PY, and the seller intends to, but is yet to purchase the new
house property as the time limit of 2 years or 3 years has not yet expired, then the assessee
is required to deposit the amount of gains in the Capital gains account scheme (in any branch
of public sector, bank) before the due date for filing income tax returns.
so you need to deposit the amount in capital gain account scheme before 31st August.

in your case die date will be 31st Aug 2019 for capital gain purpose. And hence deposit money into your bank under Capital Gain Account Scheme. Even if you file return late, you have transfer funds to Capital Gain Account Scheme within 3 days that is by 31st Aug