max no of process execeed 300

2. Check Current Setting of Parameters
 show parameter sessions;
show parameter processes;
show parameter transactions;

3. If you are planning to increase "PROCESSES" parameter you should also plan to increase "sessions and "transactions" parameters
A basic formula for determining these parameter values is as follows:

processes=x
sessions=x*1.1+5
transactions=sessions*1.1

4. These paramters can't be modified in memory. You have to modify the spfile only (scope=spfile) and bounce the instance.
sql> alter system set processes=500 scope=spfile;
sql> alter system set sessions=555 scope=spfile;
sql> alter system set transactions=610 scope=spfile;


set pagesize 500
set heading off
spool kill_inactive_session
select 'alter system kill session '||''''||sid||','||serial#||''''||' ;' from v$session where status='INACTIVE';

SQL> SET lines 200 pages 1000
SQL> SELECT *
     FROM v$resource_limit
     WHERE resource_name='processes';