STCL incorrect in original, how to correct it?

Hello

I had a  Shot term capital loss (equity) of around 500 actually in last FY, but due to my wrong calculation I claimed it as STCL around 1000 rupees and carried forward in original return done within due date.

Later I found the mistake in the calculation and now I wanted to correct this error, so please somebody tell whether it can corrected through revised return or some other way.

Thanks