Hi Rohit,
As can be seen at the bottom of the screenshot, there is some error on the page.
Can you please download and analyse the logs and traces from the server and share your findings.
Also, please try to use HttpWatch tool to analyse the Http traffic while accessing the Portal.
For more info on HttpWatch tool, please refer to the below SAP Note:
1558903 - How To Trace a Portal scenario Using HttpWatch
BR,
Anurag