Hi Vimd,
Any exemption for your CPL will depend on it's recognition by CAAS (which follows the guidelines of the JAR). I could be wrong but the following are factors that will be considered:
1. If your license is recognised by the JAR
2. If your have more than 800 hrs flying experience with Multi-engine IFR experience, you may not need to go to Jandakot.
3. If your CPL is recognised, you may only need to do the ATPL subjects and not the Tech papers (excluding radio telephony)
There is currently one indian national at the college who holds a PPL and he is exempted 40 hrs of flying (this is the basic exemption given to most cadets who hold a PPL).
Hope I have answered your questions.
Cheers and good luck.
GhosRider