Who are qualified as ‘ordinarily resident’?

What does Section 20 of the Representation of the People Act, 1950 state? Why are migrant workers vulnerable when it comes to classifying themselves as ordinarily resident in a particular constituency? Are NRIs allowed to vote? What does the Registration of Electors Rules, 1960 govern?

Who are qualified as ‘ordinarily resident’?
What does Section 20 of the Representation of the People Act, 1950 state? Why are migrant workers vulnerable when it comes to classifying themselves as ordinarily resident in a particular constituency? Are NRIs allowed to vote? What does the Registration of Electors Rules, 1960 govern?