When the TDS payment has to be on purchase of immovable property

As per Section 194 IA

"Any person, being a transferee, responsible for paying (other than the person referred to in section 194LA) to a resident transferor any sum by way of consideration for transfer of any immovable property (other than agricultural land), shall, at the time of credit of such sum to the account of the transferor or at the time of payment of such sum in cash or by issue of a cheque or draft or by any other mode, whichever is earlier, deduct an amount equal to one per cent of such sum as income-tax thereon."

Hence according to above section Tax shall be deducted at the time of each and every installment.

Interest provisions - According to Section 201

a) in case of non deduction of tax - interest is charged @ 1% for every month or part of a month on the amount of such tax from the date on which such tax was deductible to the date on which such tax is deducted

b) in case of non payment of tax - interest is charged @ 1.5% for every month or part of a month on the amount of such tax from the date on which such tax was deducted to the date on which such tax is actually paid