@Gopikrishna Karanam Thank you for reaching out to Microsoft Q&A.
- To read files from Azure Blob Storage using C#, you can use Azure Storage .NET v12 library in your Function app and refer Azure Storage samples using v12 .NET client libraries for more info.
- Then, you can store it to FileNet using FileNet.Api.dll as mentioned in IBM docs: Getting Started and https://www.ibm.com/docs/en/filenet-p8-platform/5.2.1?topic=documents-working#document_procedures__doc_procedures_create. Check IBM thread for similar info and for any specific questions on how to save the file FileNet, reach out to IBM Community experts.
Refer C# In-process and Isolated worker process docs for adding NuGet package to function app. I hope this helps with your question and please upvote if helped or add a comment if any other questions.