Automatic switch off while selecting ring tone settings,

go into settings, ring tones , and change it there , can only change to those listed,

Some how your phone was reset or had the tone turned off. Just follow the below guide and your audio should come back on. I would do a soft reset (turn off the handset, remove the battery then reinsert) before performing the instructions.

Tone settings
To select a ringing tone for voice calls, select Tones >
Ringing tone.
To select a ringing tone for video calls, select Tones > Video
call tone.
To set the ringing type, select Tones > Ringing type. You
can also set the device to sound a ringing tone that is a
combination of the spoken name of the caller and the
selected ringing tone, when someone from your contacts list
calls you. Select Tones > Say caller's name.
To set the volume level of the ringing tone, select Tones >
Ringing volume.
To set the various alert tones, select Tones > Message alert
tone, E-mail alert tone, Calendar alarm tone, or Clock
alarm tone.
To set the device to vibrate when you receive a call, select
Tones > Vibrating alert.
To set the volume level of the device keypad tones, select
Tones > Keypad tones.

I have included a link to download your user manual if needed, it comes as a PDF file so you need to have adobe PDF down loader

http://nds1.nokia.com/phones/files/guides/Nokia_E63-1_UG_en.pdf

Hello jinniq51,

i have some tips on how to do it hope it helps :D

Settings
In this menu, you can adjust various phone
settings. To reset some menu settings to their
default values, select Restore factory set.
Tone settings
Select Menu > Settings > Tone settings and from the available
options:
Ringing tone-To set the tone for incoming calls
Ringing volume-To set the volume level for the ringing and
message alert tones. If you set Ringing volume to be level 2 or
above, your phone rings with the ringing volume ascending
from level 1 to the level you have set when there is an
incoming call.
Vibrating alert-To set the phone to vibrate when you receive a
call or a text message
Message alert tone-To set the tone to sound when you receive
a text message
Warning tones-To set the phone to sound tones, for example,
when the battery is running out of power

To turn on a ringtone and vibration, go to your BlackBerry's sounds and ring tone options by either of the following ways:

1. Use the trackball to go to the sound icon in the upper left corner of the main screen and click on it, then toward the bottom of the list that appears, select Set Ring Tones/Alerts, then select Phone.

2. In the Home folder, go to your Options folder (usually toward the bottom, has a wrench icon) and select Sounds and Ring Tones.

Select the ring tone and volume that you want, and for Play Sound select Always. Scroll down to Vibration and set it for On.

There is an option for Vibrate with Ring Tone -- set that to on in order to make your phone both ring and vibrate at the same time, then save the settings when you cancel out, and you're all set.

To mute the ringing tone instead of answering a active call,select Silence.
or u can try the following

To set a mute ringing tone for a profile, select Options >
Personalise > Ringing tone. Select a ringing tone
from the list, or select Download sounds to open a
bookmark folder containing a list of bookmarks for
downloading tones using the browser. Any
downloaded tones are saved to Gallery.
To play the ringing tone for a selected contact group
only, select Options > Personalise > Alert for, and
select the option similar to none,etc...

User profiles
This is used to set up the different ways of incoming call prompts in various situations. Use
the up/down key to choose this option and click the left functional key to enter. There are
many modes of setting available and the default setting is the general mode.
To switch to a new user profile, use the direction key to select the target mode and click
“OK” to enter. Then select “activate” and click “OK” to confirm. Your phone will give an
“activated” prompt, indicating that the user profile is active. The “headset” mode does not
require activation; your phone will automatically switch to the “headset” mode if a headset
is connected to your phone, and back to the previous mode when unplugged.
You can also customize each user profile setting for your preference, the following
operations are available:
(1) Ring tone settings:
Incoming calls: Enter “user profile”, select “personal setting”, and set up the ring tone.
Power on: set up the music for power on.
Power off: set up the music for power off.
Message: set up the message ring tone when a new message arrives.
You can also download ring tones online.
(2) Volume
This allows you to set up the volume for ring tones and keypad tones. There are 7 grades
available. Enter this function and use the up/down key for testing and adjusting.
(3) Alert type
This is used to set up the alert type for incoming calls. Please select the suitable alert
types in different situations.

to set a ring tone in your phone, you must first go to any profile, open it, then select the ring tone option. from there you can select the ring tone you like.   

If settings were deleted in error... try this.
Go to PROFILES.
Make sure an audio profile (ie Normal) is selected.
For further personal settings:
Select ADVANCED.
Select (ie) NORMAL.
Scroll to PHONE and depress the pearl ball.
Select OUT OF HOLSTER and set to TONE.
Select RING TONE and select the tone you want.
Select VOLUME and set to your preference.
You might want to do the same for IN HOLSTER.

Cycle through the menu until you see ringer settings, then follow the prompts.

1. to set mp3 ring tones...

copy any mp3 file to phone ( via cable or bluetooth )
go to multimedia = go to mp3 = now play the song you want as tone,
when song is playing, select options, and select = set as ring tone

DONE and smile......

2. to set Default sound ring tones...

go to menu = my stuff = sounds =
browse the sound files when you like one , select options, and set as ring tone.....

Done and smile again... hope this helped...