I can't speak to what the DGCA is actually looking for, but a CAT III approval is an approval of the operator's entire program, not just the airplane. This includes maintenance training and procedures, spare parts control, flight operations procedures that are specific to the operator and the particular airports within the operator's route structure, crew training specific to the operator's particular procedures, and so forth.
I wrestled with this when writing and certificating a CAT III program here in the States. We were flying the 757 with a bunch of pilots who had retired early from a number of established major carriers, where they had been CAT III qualified for years. Our management had a hard time understanding why we couldn't just fly CAT III approaches out of the box. The FAA's position was not to evaluate the airplane or the pilots, but rather to evaluate how well the program we had developed within our airline met the reliability and predictability requirements of low level minimum operations.