While filing tax returns, I have forgotten to mention carried forward capital losses for the last 3 years. Returns were filed on time and assessment is complete. The revision time limit is over. 
Now, while filing returns for the next year, can I claim these losses or are they lost permanently on account of the above? 

Ans: Set off losses against income is not compulsory but it can be subject to litigation. Further, as returns are processed online, system may set off loss against gain.

Ans: Hello Purnima,

I understand your concern about the unreported short-term losses from foreign share trading for the Assessment Year (AY) 22-23. It's crucial to correct this oversight as it has a significant tax impact.

You can rectify this by filing a revised return for AY22-23. The Income Tax Act allows taxpayers to revise their return if they discover any omission or any wrong statement therein. However, please note that the revised return can only be filed if the original return was filed within the due date.

Also, remember that you can carry forward these losses to offset against future gains only if the original return was filed on time. So, if you had filed your original return for AY22-23 within the due date, you can carry forward the losses.

Please consult with a tax professional or chartered accountant to ensure that the revised return is filed correctly. This is a general advice and for a more detailed procedure, you may want to consult with a tax professional.

I hope this information is helpful.

Ans: In general, you can carry forward losses. However, to be more specific, you need to mention proper head of income under which losses are there (Business losses, Losses from house property, Losses from Stock market etc.).
Thanks.

Ans: Yes, you can carry forward Capital Loss & adjust the same in the coming years. I can't quote you specific rule, but you can carry forward the Capital Loss to next years.
Most welcome for any further clarification. Thanks.