Regarding trading loss

Sir the trading loss to be used in the proceeding year or current year is limited. by 50000 or 25% of ANI. for example in the current year we had trading loss of 70,000. because of the limit we can claim 50,000 in the current tax year. the rest of the loss i.e 20,000 can we claim it against capital gains as an extension claim? My other question is say 20/21 has ANI of 500,000 and 20/22 has 600,000(20 do we have to consider the tax year to determine the maximum limit(i.e ANI of the tax year) or the year of loss ? Hopefully I have made my question clear?