You can handle RadTooltip's onClientShow client-side event
and store a reference for each RadTooltip in an array.
More about the RadTooltip's client-side api is available on the following links:
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items