1. it is not clear from your query as to who leased the property to whom?
2. are you the owner of the property and have leased it to the builder?
3. or is the builder the owner and has leased it to you?
4. i am asking because, assuming that you are a lessee, then how can builder sub-lease the area leased to you?
5. if you are the owner and have leased the property to builder, then ofcourse the builder can sub-lease the leased premises under authority from you
6. so kindly first clear the above
7. a document which is compulsorily required to be registered like a lease deed, has to be registered with the registration office within a period of months from the date of signing the agreement which period can be further extended to another 4 months by the registrar provided sufficient cause is shown by the party for delay in registration
8. in your case the period of 8 months has already lapsed.
9.therefore both parties can sign a confirmation deed confirming the lease transaction and attach the lease deed to the confirmation deed and register the confirmation deed by paying the stamp duty with penalty if any and also registration fee. But you need to check first if this procedure is permissible in your state. In Maharashtra this procedure used to be there but presently it is not allwed.