Hi Krishna,
I think the best solution is to use the opendocument links to insert the reports in your SAP Enterprise Portal. There are other possibilities available but we also use this easy functionality. The steps are the following:
1. Create your report you want to insert in your SAP Enterprise Portal
2. Save your Report (webi, dashboard or crystal or ...) on BusinessObjects Platform
3. Go to your BI LaunchPad and right click on your report and click "Document Link".
4. Copy the document link
5. Create an URL iview in your SAP Enterprise Portal and paste the document link as URL
=> that's it! 
You can also do a lot of things with opendocument links. Please have a look on this blog post for examples: http://scn.sap.com/community/businessobjects-web-intelligence/blog/2013/03/11/how-to-use-opendocument-with-bex-variables
The official guide for opendocument links is also recommended to read: http://help.sap.com/businessobject/product_guides/boexir4/en/xi4_opendocument_en.pdf
Best Regards,
Benni