Hi @Prem chander
Usually report performance is affected by many factors. If you have deployed reports, you can check ExecutionLog3 to locate whether the retrieval, processing or rendering time is too long.
For improving report performance, you can check this link
https://learn.microsoft.com/en-us/previous-versions/sql/sql-server-2008-r2/bb522806(v=sql.105)
Best regards,
Aniya