Hi @rahul ,
Thank you for sharing the steps you took to configure cross-tenant and B2B configuration.
I understand that you are using B2B direct connect as you provide the steps. To enable B2B direct connect, both your organization and the external organization must mutually enable it by configuring inbound and outbound cross-tenant access settings. Ensure that your external organization allows direct B2B connections. If not, this is the reason why the user's email ID is not listed.
You can use B2B collaboration to add external user to Shared Channel. Your organizations will have to invite external organizations as guest users to your tenant. Guest users must accept your invitation before you can see them on your list.
Hope this helps. Do let us know if you any further queries.
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