Availability rate of 70% ? Its better than F-35... Carrier operation is not friendly to aircrafts, even more if you forgot some screw at each verifications...Let’s assume 40% (derived from 60/150), only 14 of the remaining 35 MiG-29K can be deemed available at a given time.
And that's just from the radar issue. The MiG-29K literally jars itself to death with every carrier landing. There needs to be re-alignment and replacement of components after every trap along with inspection for structural issues.
Not that it really matters because the Indian carriers themselves are almost entirely missing from satellite photos showing deployment. They might sail once or twice every year so cobbling together 14 or 15 aircraft for short stints is probably good enough.