Error on renaming database in SQL Server 2008 R2

You could try setting the database to single user mode.

https://stackoverflow.com/a/11624/2408095

use master
ALTER DATABASE BOSEVIKRAM SET SINGLE_USER WITH ROLLBACK IMMEDIATE    
ALTER DATABASE BOSEVIKRAM MODIFY NAME = [BOSEVIKRAM_Deleted]
ALTER DATABASE BOSEVIKRAM_Deleted SET MULTI_USER

1. Set the database to single mode:

   ALTER DATABASE dbName
   SET SINGLE_USER WITH ROLLBACK IMMEDIATE
   

2. Try to rename the database:

   ALTER DATABASE dbName MODIFY NAME = NewName
   

3. Set the database to Multiuser mode:

   ALTER DATABASE NewName
   SET MULTI_USER WITH ROLLBACK IMMEDIATE
   

In SQL Server Management Studio (SSMS):

You can also right click your database in the Object Explorer and go to Properties. From there, go to Options. Scroll all the way down and set Restrict Access to SINGLE_USER. Change your database name, then go back in and set it back to MULTI_USER.