Hello Mayur

It is the practice of some mills to supply oversize plates. This is because plates are sold by weight, not by guage thickness. It means that more money is involved. In my experience, this is common practice in the case of carbon steel, but rare in the case of stainless steel.

There is another possibility. The thickness tester may not have been calibrated accurately for stainless steel. Carbon and stainless steels have different characteristics. I would give this careful consideration.

I would be a bit suspicious in this case.