Yeah J-10 has different versions.
J-7 is one generation.
J-8 is another generation higher.
J-9 (cancelled)
J-10 is the highest generation of Chinese fighter jet equivalent to Su-27 and F-16's.
On top of basic J-10 version, the PLA develops/improves different other version, J-10 army version, J-10 navy version, single-engined, single seat, twin-engined, twin-seats, etc.
J-11 is the home made Su-27 series.
J-12 is the version to match JSF, F/A-22.
J-13, J-14 are all under concept design.
Since Chinese normally keeps their progress in secret, when you hear or see the jets flying then it is already under development for at least 10 years, like J-10.