Income tax return

Dear All,

I am working at Dhaka Bangladesh @ EPZ as per our contract our all tax and related liabilities will be born by the company.

Kindly advise about the ITR for the same. Need to know

Form of ITR ???

Income earned @ Bangladesh Tax Treatment for the same ???

Under which section we can claim deduction for the same ???

Last 4 years returns not filed ????

Please only experts only advise thanks