You may want to check your history.
The MKIs were ordered in 1996 and the first 8 were delivered in 1997, but those were actually old Russian Su30 jets (the full specifications for what the MKI should be was not even agreed at this point), and were deemed non-operational by the IAF.
The first batch of 10 "new built" Su30Ks were only delivered in Nov 1999, and were modified birds originally built for Indonesia, and that was the same for the next few batches.
The pre-production full spec MKI prototype did not even fly until November 2000, and the delivery of the first batch of full spec MKI prototypes did not happen until early 2002.
That's 6 years just to get the first flying full spec prototypes delivered to the customer, so I have no idea where your 2 years to get inducted figure came from.
The step up from J10A to J10B/C is actually more akin to the Eurofighter Typhoon Trench1 to Trench 4bs, and I will leave you to look up how long that is taking.