Rate of deduction for non resident U/S 194J

Please tell me

at which rate we have to deduct tds for non residents if they render service to the company based india.

Eg:

A is a indian company and B is a foreign consultant if he is rendering service to A.after completing 1 month he send bill to A for amount of 50000/-  at what rate now tds should be deducted by A and finally how much he has to pay to B.

plese respond immediately after u study this Query Little urgent.

Thanks in Advance.