TDS Deduction

One of my client has received contract for providing engineering services in Dubai He has deputed his people there who are working there till the contracts end. A fixed salary is paid to his employees from his income by foriegn compnay. He paid overtime amount from here in Indian Rupees.
Question
1) Does he require to take EEC code for providing this service?
2) Whether his income is taxable, since service is rendered outside india?
3) TDS is Applicable on salary/ overtime paid to his employees?

Please guide me in this matter waiting for ur replies