How to submit ITR for old F&O losses

For claiming prior losses (from 2021 to 2023):

Carried forward losses need to be adjusted in the current year's return if you are filing ITR-3.

You should verify if Form 1 allows carrying forward losses for those years.Typically, business losses are carried forward in ITR-3 for businesses.

If you have been filing ITR-1 (for individuals with salary income), you might not have reported business losses.. 

check with a tax professional or consult the Income tax dept. guidelines for specific on how to claim prior losses, especially if switching from ITR-1 to ITR-3.

I think you have missed the deadline for claiming past losses.

For claiming losses you have to file the tax return in time.

Loss for 24-25 you can claim by filing return in time.