Cancellation of lease deed.

Sir, We have leased out our commercial property at Patna (Bihar) to a Corporate firm for a period of 9 years through a registered lease deed. The date of commencement of lease is 01.01.2019. However, due to some reasons the lessee is not willing to take possession of the property and want to cancel the lease to which we, the lessor, have also agreed. The deed is to be cancelled wef 01.01.2019 itself. There is no rental transaction. Informatively, an amount of Rs. 1,25,000/- was spent on stamp duty and registration of the said lease deed. Would request you to kindly let us know the procedure for cancellation of lease deed. Whether exchange of cancellation consent of both the parties through letters/e-mail is sufficient for cancellation of the lease deed or we have to go for registration of cancellation of lease deed? If cancellation deed required to be registered at Patna then whether the same shall attract any Stamp Duty and Registration charges? If so then what amount? Further is there any provision of getting refund of the stamp duty paid at the time of registration of the said lease deed? If so then kindly let us know the procedure. Shall appreciate your early advice. Thanking you, Yours truly, Y. D. Shriswamy.