On this touch-stone, and hallmark, the IRS market in India is then a non-derivative, nay, a financial innovation that never was. Credit Default Swap (CDS) Like Interest Rate Swap, or for that matter any other derivative, Credit Default Swap is no exception to cash market replication principle of derivatives pricing.
Without going into mathematical gymnastic proper, price of a CDS, in spread terms, is reasonably approximated by the difference between the spread of a reference bond to corresponding maturity G-Sec yield and the spread of IRS to the same maturity G-Sec yield.