Default code for Nokias is 12345. This will work if you did not change access code.
If you set up your own access code, you can recover the code by connecting to computer or using a file manager. You can download Fileman here.
After installing file manager check the folder C:Systemmmcstore . Rename file mmcstore.txt and send it to another mobile or to your PC via bluetooth or USB, open it and there you will find the password.
Here is also a reset procedure that works on some Nokia, I do not know if it is good for 6300.
Beware, by using reset below you will delete all data stored in phone memory, even phone numbers if they are stored in phone memory:
Take the SIM card out.
Make sure your phone battery is fully charged.
Press * 3 send at the same time and turn the phone on.
Keep this two buttons pressed until the reset screen appears.
Wait some time to reset.
Switch phone back on.
By Mr.GINKO plz do rate this post
Source: nokia 6230i security code
my imei 359820012968226