If you are using RadToolTipManager with Load On Demand, the content controls will not be added to the page until the response of the request. If you are simply using a separate RadToolTip control, you can directly use $get or $find to find the corresponding HTML elements or client objects. please, note, that if you have an INaming Container you should evaluate the actual client ID but the tooltip itself is not changing the IDs.
In case you need further assistance, please provide some runnable code along with detailed explanations and I will modify it in order to meet your requirements.
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