Yogeeta,
The change control system is used to track, approve, and/or reject changes to the project baselines (cost, schedule, scope). You would not need to issue a change request in order to update the stakeholder register; this would waste your time as a PM.
Update the project's change log after approval from the CCB; however, you can also make what I like to call a "ghost note" or unofficial entry into your own personal change or issue log to track changes internally while they are routing through the CCS. However, keep in mind that's not an answer for the actual exam!
- Steven