Hello Mounika, many thanks for your question, are you using a shared access cluster? If yes, shared clusters requires you to grant Select permission on Any file to be able to access DBFS as mentioned on this doc https://docs.databricks.com/en/data-governance/table-acls/any-file.html#how-does-any-file-interact-w...
You can grant this permission by running https://kb.databricks.com/en_US/data/user-does-not-have-permission-select-on-any-file 

Another solution will be to use single user cluster which does not requires it.