gst query

If Your turn over is less than 1.5cr then no need to fill HSN details...

If Your turn over is above 1.5cr then HSN details is compulsory. If You are missed then no way for changes.
But, Avoid the mistake in next GSTR 1 return. No need to worry about the mistake. In case AO ask the details then give your reply as per your mistake. They will give a chance.