When using blind transfer we are able to transfer UUI from one agent to another but when using conference we are not able to see uui getting passed in the 2nd agent using the agentviewapp..
Where can we trace this issue?

You can increase the JTAPI client-side debugging so that the TSAPI events and resulting JTAPI events will be output to the log file. You can get details of this in the Debugging section of the JTAPI programmers guide.

When a call is transferred or conferences, two calls become one call. This means that one call is dropped and the other continues. Which call continues and how data is merged into it from the dropped call can depend on how the transfer or conference is performed. If UUI is not included in the main body of the continuing call, you may find it in the Original Call Information (OCI) part.

Martin