Help With FONT

Hello

I am making a site in bengali. Now, I have all the unicode fonts such as SolimanLIpi, Rupali etc.
which is like any other font available from googlefont of other source.

Now, Client asked to get SutonnyMJ font. which I remember I used use like 7/10 years ago in PC for writing bengali using specialised keyboard/ keyboard software.

client has this font installed in his PC and when writing using that font some wired symbol coming up like this : Lv‡j`vi Kvh©vj‡q Avmv-hvIqv eÜ | but when I select them and change the font family to sutonny it looks ok but breaks other things. specially if their any english writing.
I only can change body this way, I have no control over on title and breadcrumbs appearance therefore those wired symbols appearing.

I am real confused here. How can I solve this issue ?

Regards
Plaban