Union Government
Members of either House of Parliament shall be entitled to receive such salaries and allowances as Parliament may from time to time determine by law, and until so determined, at the rates and conditions applicable to members of the Constituent Assembly of the Dominion of India immediately before this Constitution's commencement.
MPs' pay is set by Parliament itself through ordinary legislation, not fixed permanently in the Constitution - this gives Parliament flexibility to periodically revise MP salaries and allowances as it sees fit.
This is the constitutional basis for the Salary, Allowances and Pension of Members of Parliament Act, which Parliament periodically amends to revise MPs' pay, housing, travel, and other allowances.