(2)In the case of any class of assessees, where the Finance Act of the relevant year provides that, net agricultural income shall be taken into account for the purposes of computing advance tax, then,––(a)for the purposes of order as mentioned in section 407(1) and (4), the net agricultural income shall be the amount that has been taken into account for the purposes of charging income-tax on the specified sum as mentioned in sub-sections (3) and (6) of the said section; or(b)in any other situation, the net agricultural income as estimated by the assessee for the tax year.