How much rebate under section 87A for FY 2018-19

For net total income upto 3,50,000/- rebate is upto 2,500/-

Rebate u/s 87A is 2500 income after all deduction ie u/s 80C is before adding 4% education cess & health cess

total tax liability =
tax on total income at applicable rates. +

surcharge at applicable rates, if total income exceeds rs 50 lakhs +

Cess @ 4% (-)

rebate u/s 87A, if total income is less than rs 3.5 lakhs