Hi Prabaharan,
I see we are solving same issues, since yesterday your question about slug helped me.
First make sure you are returning the entity as described here: How To Upload and Download Files Using SAP NW Gateway SP06 - 20140127 Updated code below to perform correct read after upload.
Then, I believe you have to extend Model Provider Class as stated here: How to Read Photo from SAP system using SAP NetWeaver Gateway and use code from here: SAP NetWeaver Gateway Service Builder: How to Read Photo - Code Snippets
Then regenerate runtime objects in segw and it should work.
If it does not, try to implement get_stream as well, even though I think extension of MPC should do its job.
Regards,
Peter