Since this is not a standard Unicode font, you cannot simply switch your system language. You must use a transliteration tool.
The font is typically distributed as a ZIP archive containing the TrueType Font (.ttf) file.
: This free software supports "DCI+Tml+Ismail" encoding.
Use a font manager app like or HiFont from the Google Play Store to apply the font. Note that some devices may require a reboot. How to Type Using DCI TML Ismail Keyboard