Hi Bharath,
If I remember correctly, certificate error is displayed on one of Chrome's internal pages with no external access allowed. So TestComplete cannot identify and work with controls on this page.
An obvious but fragile workaround is to use image recognition and 'blind' coordinate-based clicking using the LLPlayer object in TestComplete.
If you experience this problem with only new tests workstations and new test workstation is a rare event, you may require initial manual navigation to the site and its inclusion to the trusted sites list.
One more possible approach is to search for some admin script (using VBScript, powershell, etc.) that adds problematic site to the list of trusted sites for Chrome and execute this script before first functional test in TestComplete.
