Services
(1) There is a Union Public Service Commission (UPSC) and a Public Service Commission for each State. (2) Two or more states may, by their own legislatures' resolutions, ask Parliament to create a single Joint State Public Service Commission serving them together. (3) Parliament's law creating a Joint Commission may include incidental/consequential provisions. (4) The UPSC may, with presidential approval, agree to serve a requesting state's needs too. (5) Constitutional references to "the" UPSC or a State Commission are read as referring to whichever Commission actually serves that need.
This creates India's independent civil service recruitment bodies - the UPSC at the national level and a Public Service Commission in each state - with flexibility for smaller states to share a single Joint Commission, or even have the UPSC itself serve their needs, rather than every state necessarily needing to run its own full independent commission.
This is the constitutional basis for the UPSC (which conducts India's Civil Services Examination) and each state's own Public Service Commission (which recruits for state government positions), giving India's civil service recruitment genuine independence from direct political/executive control.