sale of fixed assets and reinvestment in fixed assets

If you have bought flat against plot in the same year in which plot was sold before last date of filing of ITR of that year then you can claim exemption under section 54F but subject to condition that either you have no other residential property or only one residential property before this sale in your hand. If this condition is fulfilled then you can claim exemption under section 54F and you don't need to pay any tax for such gain on plot.
Also loan repayment anoint throughout the year can be taken as deduction under 80C and interest paid on such home loan can also be taken as deduction under house property head every year. Only the portion of loan repayed and interest paid on loan can be taken for this detail you can get certificate from bank also every year
So I don't think you have to pay any tax if everything is as per above conditions and you don't have any other income