The Rajasthan Lokayukta and Up-Lokayuktas Act, 1973 came into force on:

A statute's operative date - when it "comes into force" - is usually distinct from the date it is passed by the legislature or receives assent. Most Acts carry a commencement provision (commonly an early section, e.g. Section 1) that either states the Act takes effect immediately or fixes (or empowers an official notification to fix) the exact day from which it is deemed to be in force.

The Rajasthan Lokayukta and Up-Lokayuktas Act, 1973 was enacted in 1973, but its commencement clause fixes the day it is deemed to have come into force as 3rd February, 1973. This date is independently corroborated by the Rajasthan Lokayukta institution's own published history, which records 3rd February, 1973 as the day the Act took effect.

• 3rd January, 1973 falls within the enactment year but is not the day named in the Act's commencement clause.

• 3rd May, 1973 also falls within 1973 but is likewise not the day fixed for the Act's commencement.

• 3rd June, 1973 is within the same year but is not the commencement date recorded in the statute or the Lokayukta's institutional history.

Cross-checking against both the Act's own text and the Lokayukta office's institutional record confirms 3rd February, 1973 as the sole date supported by primary sources, so that is the correct answer.