1. If you have the folder e: resource, create inside a new folder, Fonts
2. if not, Make folder on mem card as follows: [mem-card]:Resource/Fonts
3. Pick TTF font for example verdana.ttf from PC 4 times and rename these files to
nohindisnr60.ttf
nohindissb60.ttf
nohinditsb60.ttf
S60ZDIGI.ttf
4. Copy these to newly created folder
5. You can use any TTF in this purpose
6. Recomended is usage of hi-quality fonts which support full range of code pages
9. Reboot phone
10. Enjoy!!!!!!!
Otherwise, you can use Y-browser to change fonts
Source