AVRO keyboard is actually needed for the job. You will need the ANSI version of Bengali font.
Download ANSI fonts: Siyam Rupali ANSI or Kalpurush ANSI and place them in C:\Windows\Fonts then go to Avro Settings > Output as ANSI > Use ANSI anyway. Go to Photoshop and enable Text tool, select the font and you can type in Bengali.