In order to get a font of the regional language you will first need to Root your device.
Follow this in order to understand what does rooting a device mean and this question on how to root.There is one more site which is providing rooting specific to your device
- After you have rooted the device then you need a file manager
application like ES file Explorer
- Now download the font
- Open Es file explorer (give root access open the file
explorer>Config > Give root access)
- Copy your font file and paste it to (Root)/System/Fonts
- Set permissions as 644 or RW.
- Reebot/Restart your device.
Now if you want to give gujrati as the input font download the keyboard app from the play store.
Rooting your device will void your warranty and you will be doing on your own risk. Please understand the risk's or data loss involved and go ahead only when you have the complete knowledge of it.