Based on my test, I can find the total number of sink(consumer application) open calls for RICs from adsmon(ADS Monitoring). After adsmon starts, press J to go down and select User Statistics then press Enter.
At Lists of Users which shows the users connecting to ADS currently, you will see OpenItems of each user as example below:
From the picture, at that moment 2 users subscribed 4 and 3 RICs.
For more details of adsmon, please refer to adsmon: ADS Monitoring section in ADS installation guide e.g. ADS_Install_33x.pdf
If the customer requires any help about adsmon, ADS or ADH. Please contact TREP support team who is expert in TREP by submitting the query via Get Product Support on MyRefinitiv. If the customer faces any difficulties submitting the query, please contact Refinitiv Account team.
There are no APIs available to query the TREP components. The customer will have to reach out to their market data team managing the TREP servers to provide details related to what the ADS/ADH are consuming. I believe the components do have monitors that provide an assortment of statistics.