§530
Section 530 — Act to have effect pending legislative provision for charge of tax
In plain terms: This section says that if a Central Act has not yet fixed the rates of income-tax for a tax year by 1 April, the Act still has effect and the Act has effect until the provision for charging tax is made.
If on the 1st April in any tax year, provision has not yet been made by a Central Act for the charging of income-tax for that tax year, this Act shall nevertheless have effect until such provision is so made, as if the provision in force in the preceding tax year or the provision proposed in the Bill then before Parliament, whichever is more favourable to the assessee, were actually in force.