Even INDIA has an Indigenous Engine. So What ?
The problem is It doesnt meet the needs. needs = "mastering" , the technology.
For India, its F414 ( despite having kaveri )
For China is RD 93s / AF41s /117s ( despite having WS Series )
https://thediplomat.com/2015/06/why-chinas-air-force-needs-the-su-35/
PLAAF’s primary motivation for buying the Su-35 may not be for its value as a weapons system but rather because it is equipped with advanced AL-117S turbofans.
Engines are a critically important component of any fighter aircraft, and they present Chinese airplane manufacturers with a dilemma. Their new fifth-generation fighter prototypes, the Chengdu J-20 and Shenyang J-31, sport sophisticated airframes and avionics that are clearly intended to make them a match for the United States’ most advanced aircraft.
However, China’s ability to manufacture jet engines has not kept pace with other sectors of its aerospace industry. Regardless of how capable other Chinese aircraft systems may be, without a reliable, high-performance turbofan engine to power them, both the J-20 and the J-31 will be crippled.