The current Indian DGCA FDTL scheme is old and unsophisticated. The 1992 scheme document is here:
http://dgca.nic.in/aic/aic28_92.pdf
For example, there is no allowance made for start time so the same limit applies for duty starting at 2300 as for a duty starting at 0900. In addition, the airlines have managed to get a waiver of the international flight time limits for a 2 pilot crew from 9hours flight time and 12 hours duty time to 10hours flight time and 14 hours duty time.
On 27th July 2007, a revised scheme was introduced which stayed in operation for less than one year. It gave considerabley more time off between flights, but did not do anyting to reduce the length of the duty and flight times permitted for 2 pilots operation. That scheme is still suspended.
There seems to be an intention to adopt the latest EASA scheme when that becomes operational in Europe.
Finally, the concept of "captain's discretion" is completely different to the EASA scheme and barely is worthy of the same title!