I'm in an older super cuts that still uses the old 3 lamp f32t8 troffers one lamp is flickering on one side about 3" or so from the end and it has rings in in to about the center of the lamp. The other end is fine as are the other 2 lamps and fixtures I assume instant start but not 100% sure as I didn't see them get turned on.

Does it uses electronic (HF) or magnetic (60Hz) ballast?

With an electronic the arc sometimes tend to swirl and dance on the electrode, yielding some flicker there. Sometimes it goes away after some hours of an uninterrupted burn, sometimes it likes to stay dancing.

With magnetic it could mean one cathode is dying (but still able to hold the arc), so causes the cathode dark band to be larger, so that section then glows only when that side is the anode, so the 60Hz flicker.

Unless it gets annoying, you dont have to worry about that.