Solution to set mp3 song as ringtone in samsung galaxy y duos GT-S6102.

Here's how to set your mp3 as Ringtone:

1. Open any File Manager App

2. Look for folder called "Media" in phone's main directory.(Mostly it doesn't exist, so create it by right clicking & choosing "New folder", then Rename the folder to "media")

3. Inside the "Media folder", you need a folder "Audio". Again if it's not there create it as above.

4. Inside the "Audio folder", create subfolders for the sound categories you want to change:

=>"Ringtones" for the sound files you want to use for incoming calls
=>"Alarms" for the sound files you want to use for alarms
=>"Notifications" for all other alerts such as incoming SMS, emails or alerts from individual apps, etc.

Note==> Lower/Upper case is irrelevant-the folders can be "MEDIA", "Media",  or "media" etc.