Services
(1) The UPSC/State Commissions conduct examinations for Union/State service appointments. (2) The UPSC assists states with joint-recruitment schemes for specialised roles, if requested. (3) The relevant Commission must be consulted on recruitment methods, appointment/promotion/transfer principles and candidate suitability, civil-service disciplinary matters, legal-defence-cost claims, and injury-pension claims - though the President/Governor can make regulations exempting certain matters from this consultation requirement. (4) Consultation isn't required for reservation-related matters under Article 16(4) or Article 335. (5) Regulations exempting matters from consultation must be laid before Parliament/the State Legislature and can be modified by them.
This defines a Public Service Commission's core job: running recruitment exams, and being consulted (though not necessarily having the final say) on a wide range of civil service matters from hiring to discipline to pensions - independent expert input built into the government employment process, though not an absolute veto power.
This is why the UPSC's role goes well beyond just conducting the Civil Services Examination - it's also meant to be formally consulted on disciplinary actions against civil servants and various other personnel matters, giving an independent check on purely political decision-making in these areas.