Is there any API available in IDN to aggregate only one account from Active Directory Source ?
Yes, you can use the V3 accounts API to do a single account aggregation. In order to get the ID of the account you want to aggregate you will first need to find the ID of the source the account resides in, and then find the ID of that account on the source. Both of these endpoints provide a
filter query parameter that will allow you to narrow down your results.