How to create RESTRICTED Session in Oracle DB

Apart from Startup nomount , Startup mount, or Startup [open] there is one more mode to start the Oracle DB Instance is 

Startup Restrict 

or 

Alter system enable restricted session;

How can user create session

When database is OPEN  i.e. startup open , users must be grant CREATE SESSION to Connect 

grant create session to yogesh;

When database is restricted mode, users must be grant create session as well as create restrict session.

grant create restricted session to yogesh;

Note - > if user already logged in and dba issue alter system enable restricted session; command then those user remain logged in.

Disable restricted mode

alter system disable restricted session.