How To Calculate Local Time Of A Sun Synchronous Orbit With A Given Altitude ( Say 600 km ) , Inclination ( 98 degrees ) ?
The local time can be whatever you choose. It is not something you calculate.
In order to be able to maintain a fixed local time with very little propellant usage, the inclination has to be a particular value for any given altitude. What you can calculate is the rate of change of the local time as a function of the altitude and inclination.