Chinese wanted a less sophisticated version than Indian Su-30MKI with canard a better new radar, Bars also Israeli and French electronic in fact a new customized variant, coz Chinese want Su-30MKK available faster.
And Indians wished their Su-30 not manufactured in the same plant, for some reasons...
The first after kits build in Russia and assembled by HAL in India as for Su-27/J-11 build under license by Chinese.
