I used Interactive report APEX_ITEM.CHECKBOX2(p_idx => 1, p_value => ST.ID, p_attributes => DECODE(ST.IS_HEADER_ROW ,'Y', 'DISABLED',NULL)).
And I want to use highlighted IDs depending upon checks in Row ID field in Comma delimited format DYNAMICALLY.
Further I will use that Row IDs value in another region report and will update values in DB after few validations.
On button press, you could run this JavaScript which concatenates all nominated checkboxes into a delimited string.
Then use the following query to find all the records matching values in that string using this, or your version's equivalent.
This can all happen without submitting the page.