Welcome @sujanadh!
You can update any property by specifying its name in the save_to column of your XLSForm. See the documentation for more details.
You could do this by specifying submission_id in the save_to column for a calculate field with calculation ${instanceID}:
| type | name | label | save_to | calculation |
|---|---|---|---|---|
| calculation | this_sub | submission_id | ${instanceID} |
However, before you do this, I recommend that you review In analysis, how can I connect an Entity registration form's submissions to follow-up form submissions? for some alternative ideas.
If you say more about your desired way to use the data you're collecting, we can explore the best approach for your case.
We'd love to learn more about what you work on. When you have a moment, I invite you to introduce yourself. Thank you!