unable to calculate withholding tax for rent payment

Summary:

Tax withholding on Rent Payment Scenario: Let's say we have 12 lac annual rent which makes 1 lac per month. But, the practice in Pakistan for calculating the tax liability will be like that we check the slab in which the rent is falling, let's say it falls between 6-20 lac slab on which 10% is applicable. The tax liability calculated will be (12 lac-3 lac which is excluded)= 9lac on which 10% will be applied it will make 90k. Now, we divide 90k with remaining months for tax year end ( let's assume we acquire the building on