Filezilla ftp

i just uploaded a altered html file but the now page became unreadable. Kindly give a solution

It is Japanese font

That is not problem of your FTP client that is problem on your web hosting side.
Can you contact your web host about that and ask to have a look?

Thank you for your kind reply. if i correct the html file with dreamweaver etc can solve this problem?

Maybe. Try to test them on your PC locally using the same browser

I had the same problem with multilingual website
Open your file and resave it with the right encoding format then upload it again.
That would fix the problem.