Generally, migrant workers, especially those who are hired through recruitment agencies, are exempted from paying taxes in the host countries. If your income is taxable, this should be clearly indicated in the contract. The usual practice is also for the employer to deduct the taxes from your salary so that you will receive the net amount and you do not need to pay personally the taxes.
In Bangladesh Government deducted 10% tax on remittances and provides 2% incentives on remittances. Check with the MRCs for additional information on this matter.