"You can save the capital gain tax by investing only the amount of capital gain after indexation benefit in new house. In other words it is not necessary to invest the entire proceeds from sale of house to save capital gain. However, if you need money for buying house than you can invest entire sale proceeds.
If the house is not let out for a minimum of 300 days during the financial year than it will be liable for wealth tax @1%. This is applicable as per present law and there is no change proposed in DTC for vacant house. So ensure the occupancy more than 300 days for rented property."