Should I post this on currency exchange board or maintain a thread in other location board?
You have a
Bangladesh exclusive thread and you might want to ask them with your matter. Also, you can ask queries in
Marketplace or particularly in
Currency Exchange Section, and upon posting, make sure that you cleared your intentions with your subject and of course the country you reside.
I also found on the Internet that
Paxful (
https://paxful.com/buy/bitcoin/bangladesh) offers transactions in your place instantly.