Regarding output voltage overshoot

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Vout = 12 V, Iout= 6 A
IC = TOP 271
My output voltage overshoot is more than 5% of rated output what should i do to restrict it to <5% .
is there i have to adjust output compasation at TL431 ?

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at power on time and 10% load.

The 100nF cap (C20) without any series resistor is probably slowing down the loop response. A better combination would be 100nF in series with 3.3-4,7k. If that is done, I'm not sure that C16 and R23 will even be necessary.
Adding a "soft finish" network across the TL431 curbs the output dV/dt during startup and helps prevent output overshoot. An example is shown in the attachment. The soft finish network is D9, R16, and C20. The C20 value may need adjustment for your particular application.

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