Dear Sohail,
By raising the question who will sign Form 16 will not solve the problem. HR is deducting the TDS and Accounts is depositing the same with Govt Treasury. Morally both are equal responsible. Only signing the Form 16 is formality. Your management should identify the authority for signature of Form 16.
Usually the person who is making the payments is responsible for this. While registration with TDS the name address of the person has to be defined. In your case the same must have defined.
Ramakant.