Registration of old document

Hi.

I had purchased a flat  in bandra, mumbai in 1997. The  Agreement for sale fo stamped for RS 13250/- and signed by the builder and myself, but due to some circumstances the same was not registered.

Now i want to know if i can register the said document by paying the registration fees ? if yes then what is the procedure ?

If not then what do i do now ?

Please advice.

Regards