Hi,
Hope you are doing well !
You can transfer the money in the capital gain saving deposit before the due date of filing your return of income.
Normally, the due date of filing Income Tax return is July 31 for the previous Financial Year.
For example, if you have sold the property on Sept, 2018 then you can keep capital gain in account till 31st July 2019.
Thanks & Regards,
Payal Chhajed