Who has authority to register property papers collector/subregistrar

I had purchased a flat at Borivali w in 2009 .The work was very slow and till today no OC. Builder has taken 90% cost.recently he called for registration and asked to pay stamp duty and registration fees .We paid rs 480000 for 55.5 square meter carpet .Sub registrar did not accept instruments saying that he has no power to register the same .Only collector can do that PL give correct position and penalty if any