It seems the only domestic Indian airline that might entertain through-ticketing and baggage from QF would be Vistara, which has its hub in DEL so would be an ideal choice. Unfortunately they are part-owned by SIA, so I expect that would put the kibosh on any such agreement? Air India is awful for many reasons and as a *A member I assume would also not be interested, although I guess that doesn't totally rule it out? (QF has plenty of interlining on UA in the US for example).
I agree with others that the value proposition for south India is poor connecting through DEL. If they had chosen BOM, you could kind of get away with it for some passengers, but for trips to MAA or BLR, I would probably continue to use SIN/KUL or even HKG for my business travel, if it gets up again.