Thank you for contacting Syncfusion support.
We have tried to reproduce the reported image rotation problem when executing mail merge with the rotated image in DocIO, but it preserves properly with the actual rotation. For your reference, we have prepared a sample application to execute mail merge with the rotated JPG image and it can be download from the below link:
We suspect that the problem might be due to image and the input Word document used at your end. So, could you please provide us the following things from your end:
1. Modified sample of above along with input Word document and images used at your end.
2. Expected output document.
This will be more helpful to check on the reported problem and then we will provide you the appropriate solution at the earliest.
Note: If you have any confidential data in your Word document, please replace with some dummy data and provide us the same. We just need your document to recreate the problem you face.
Please let us know if you have any other questions.